Wafaiya YanbuRCJY answers
Home›Item 08 · Site studies – sun path and wind›Quarterly climate analysis
08

Site analysis · supplement to the Autodesk Forma studies

Quarterly climate analysis – Yanbu

How the Red Sea climate at the site changes through the year, quarter by quarter – from the official station normals and 34 years of reanalysis data – and how the design answers each season.

Station normals 1991–2020 (WMO)ERA5 reanalysis 1991–2024Trend projection to 2030

The year in four quarters

Temperatures and rain from the Yanbu station normals; humidity, wind, sun, comfort and the warming trend from ERA5 at the waterfront.

28.2 °Cannual mean (station)
51.0 °Crecord high, July
39.5 mmrain a year, 3–4 rain days
≈ 3,700cooling degree days (base 18 °C)
Q1

Cool and comfortable season

Jan–Mar

29.3°mean max
15.7°mean min
10mm rain
80%comfortable hours

Outdoor season: terraces, pool decks, roof café and al fresco dining in full use; north-westerly sea breeze of 4–7 m/s in the afternoon; the first winter rain and rare flash-flood events (Jan).

Design response

  • Open the roof venues and podium decks for daytime use; wind screens 40–50 % porous on the W–NW edges (Forma roof study).
  • Pool and deck heating not needed; light shading is enough.
  • Roof and podium drainage sized for short intense storms; falls to outlets and overflow scuppers.
Q2

Heating up – sea-breeze season

Apr–Jun

38.0°mean max
23.5°mean min
1mm rain
27%comfortable hours

Mean max 38 °C; the afternoon W–WNW sea breeze is strongest (7–8 m/s at 15:00–17:00); dust and haze events; dry mornings.

Design response

  • Bronze khatam screens and deep sawtooth balconies cut the west and south-west sun in the afternoon.
  • Use the sea breeze: shaded west terraces and pool decks usable in the late afternoon and evening.
  • Sand-trap louvres and filtration on fresh-air intakes; cooling plant moves to summer duty.
Q3

Peak heat and humidity

Jul–Sep

40.5°mean max
27.1°mean min
0mm rain
1%comfortable hours

Mean max 40.5 °C (record 51.0 °C), nights stay near 27–28 °C, humidity peaks (dew point ≈ 23 °C) – hardly any comfortable outdoor hours; peak cooling load.

Design response

  • Design cooling load and plant sizing on Q3 (≈ 38 % of the yearly cooling degree days); SHGC ≤ 0.25 glazing and U ≤ 0.34 walls.
  • Outdoor life moves to early morning and late evening; shaded, misted and fan-assisted terraces; indoor pool and fitness alternatives.
  • Condensation control on cold surfaces and at the glazing in humid nights.
Q4

Mild, wettest quarter

Oct–Dec

33.3°mean max
19.9°mean min
29mm rain
51%comfortable hours

Mean max 33 °C falling to 30 °C by December; comfortable evenings return; most of the annual rain (≈ 29 of 39 mm) falls in Nov–Dec in a few heavy events; NE winds return.

Design response

  • Outdoor season re-opens from November; terraces and roof venues in evening use.
  • Storm-water drainage, basement ramp entrance trench drains and podium waterproofing checked for the Nov–Dec storms.
  • Native, drought-tolerant planting re-establishes with the winter rain; TSE drip irrigation reduced.

Quarterly summary

QuarterMean max °CMean °CMean min °CRecord max °CRain mmRH %Dew point °CWind m/sPrevailing wind (from)Sun h/daySolar kWh/m²·dayCooling degree daysComfortable hoursNights ≥ 28 °C
Q1 · Jan–Mar29.322.315.740.09.55512.14.6WNW, NW10.75.539280 %0
Q2 · Apr–Jun38.030.623.549.60.95618.64.8WNW, W12.67.5114427 %20
Q3 · Jul–Sep40.533.427.151.00.16122.65.0W, WNW12.16.914141 %65
Q4 · Oct–Dec33.326.319.947.428.95816.84.0WNW, NW10.54.976451 %4

Rain, record and mean temperatures: Yanbu station (WMO 40439), 1991–2020. Humidity, dew point, wind, sun and solar: ERA5, 1991–2020. Comfortable hours and nights ≥ 28 °C: ERA5 hourly, 2015–2024. Cooling degree days from the station monthly means.

Temperature through the year

Mean daily maximum, mean and minimum by month – Yanbu station normals 1991–2020. Hover a month for the values and records.

Q1Q2Q3Q410°15°20°25°30°35°40°45°Mean max 29.7°Daily mean 22.6°Mean min 16.2°Jan: mean max 27.6 °C · mean 20.8 °C · mean min 14.3 °C · record 35.0 / 4.7 °CJanFeb: mean max 28.9 °C · mean 21.9 °C · mean min 15.3 °C · record 37.3 / 6.5 °CFebMar: mean max 31.5 °C · mean 24.3 °C · mean min 17.4 °C · record 40.0 / 8.7 °CMarApr: mean max 34.8 °C · mean 27.7 °C · mean min 20.8 °C · record 44.4 / 11.5 °CAprMay: mean max 38.5 °C · mean 31.1 °C · mean min 24.1 °C · record 49.0 / 15.6 °CMayJun: mean max 40.7 °C · mean 32.9 °C · mean min 25.7 °C · record 49.6 / 18.0 °CJunJul: mean max 40.5 °C · mean 33.4 °C · mean min 27.0 °C · record 51.0 / 21.3 °CJulAug: mean max 40.8 °C · mean 33.9 °C · mean min 27.9 °C · record 49.5 / 20.4 °CAugSep: mean max 40.2 °C · mean 32.8 °C · mean min 26.5 °C · record 49.0 / 19.0 °CSepOct: mean max 37.2 °C · mean 30.2 °C · mean min 23.9 °C · record 47.4 / 14.3 °COctNov: mean max 33.1 °C · mean 26.1 °C · mean min 19.7 °C · record 44.7 / 12.0 °CNovDec: mean max 29.7 °C · mean 22.6 °C · mean min 16.2 °C · record 42.0 / 7.8 °CDec
Monthly data table
MonthMean max °CMean °CMean min °CRecord max / min °CRain mmRain daysRH % (ERA5)Wind m/sSun h/daySolar kWh/m²·day
Jan27.620.814.335.0 / 4.76.50.653.94.110.44.5
Feb28.921.915.337.3 / 6.51.80.254.44.210.75.4
Mar31.524.317.440.0 / 8.71.20.356.14.2116.4
Apr34.827.720.844.4 / 11.50.30.158.63.912.17.3
May38.531.124.149.0 / 15.60.60.156.24.112.77.6
Jun40.732.925.749.6 / 18.00.00.053.74.6137.6
Jul40.533.427.051.0 / 21.30.00.059.74.212.97.3
Aug40.833.927.949.5 / 20.40.10.160.94.312.37.0
Sep40.232.826.549.0 / 19.00.00.061.74.011.26.4
Oct37.230.223.947.4 / 14.33.60.463.33.510.95.6
Nov33.126.119.744.7 / 12.012.11.158.13.510.34.8
Dec29.722.616.242.0 / 7.813.20.653.83.910.34.3

Outdoor comfort by quarter

Share of all hours by heat stress (heat index from temperature and humidity), ERA5 hourly 2015–2024 at the waterfront. Q1 is the outdoor season; Q3 has almost no comfortable hours, day or night.

Cool (< 18 °C)ComfortableWarm (HI 29–35)Hot (HI 35–41)Extreme (HI ≥ 41)Q1 Jan–MarQ1 · Jan–Mar: Cool (< 18 °C) 14.7 % of hours15%Q1 · Jan–Mar: Comfortable 79.7 % of hours80%Q1 · Jan–Mar: Warm (HI 29–35) 5.6 % of hoursQ2 Apr–JunQ2 · Apr–Jun: Cool (< 18 °C) 4.8 % of hoursQ2 · Apr–Jun: Comfortable 27.3 % of hours27%Q2 · Apr–Jun: Warm (HI 29–35) 44.6 % of hours45%Q2 · Apr–Jun: Hot (HI 35–41) 20.7 % of hours21%Q2 · Apr–Jun: Extreme (HI ≥ 41) 2.6 % of hoursQ3 Jul–SepQ3 · Jul–Sep: Cool (< 18 °C) 0.5 % of hoursQ3 · Jul–Sep: Comfortable 1.3 % of hoursQ3 · Jul–Sep: Warm (HI 29–35) 26.0 % of hours26%Q3 · Jul–Sep: Hot (HI 35–41) 47.9 % of hours48%Q3 · Jul–Sep: Extreme (HI ≥ 41) 24.3 % of hours24%Q4 Oct–DecQ4 · Oct–Dec: Cool (< 18 °C) 7.3 % of hours7%Q4 · Oct–Dec: Comfortable 51.4 % of hours51%Q4 · Oct–Dec: Warm (HI 29–35) 26.8 % of hours27%Q4 · Oct–Dec: Hot (HI 35–41) 12.7 % of hours13%Q4 · Oct–Dec: Extreme (HI ≥ 41) 1.8 % of hours

Evening hours (17:00–23:00) that are comfortable: Q1 93 % · Q2 20 % · Q3 0 % · Q4 48 %.

Wind by quarter

Wind roses from ERA5 hourly data 2015–2024 (10 m). The sea breeze from the W–NW dominates all year and is strongest in Q2–Q3 afternoons; NNE–NE land winds return in Q4–Q1 nights.

12%24%NESWQ1 · Jan–Mar – from N: 3.7 % of hours (1–2: 0.8%, 2–4: 2.3%, 4–6: 0.6%, 6–8: 0%, ≥8 m/s: 0%)Q1 · Jan–Mar – from NNE: 4.7 % of hours (1–2: 0.9%, 2–4: 2.7%, 4–6: 0.9%, 6–8: 0.2%, ≥8 m/s: 0%)Q1 · Jan–Mar – from NE: 10.9 % of hours (1–2: 1.4%, 2–4: 3.5%, 4–6: 2.9%, 6–8: 2.1%, ≥8 m/s: 1%)Q1 · Jan–Mar – from ENE: 6.4 % of hours (1–2: 1%, 2–4: 3.3%, 4–6: 1.3%, 6–8: 0.7%, ≥8 m/s: 0.1%)Q1 · Jan–Mar – from E: 4.7 % of hours (1–2: 0.8%, 2–4: 3.3%, 4–6: 0.5%, 6–8: 0.1%, ≥8 m/s: 0%)Q1 · Jan–Mar – from ESE: 2.9 % of hours (1–2: 0.6%, 2–4: 1.8%, 4–6: 0.5%, 6–8: 0%, ≥8 m/s: 0%)Q1 · Jan–Mar – from SE: 1.8 % of hours (1–2: 0.5%, 2–4: 1%, 4–6: 0.3%, 6–8: 0%, ≥8 m/s: 0%)Q1 · Jan–Mar – from SSE: 1.5 % of hours (1–2: 0.3%, 2–4: 0.6%, 4–6: 0.4%, 6–8: 0.1%, ≥8 m/s: 0.1%)Q1 · Jan–Mar – from S: 1.8 % of hours (1–2: 0.4%, 2–4: 0.7%, 4–6: 0.6%, 6–8: 0.1%, ≥8 m/s: 0%)Q1 · Jan–Mar – from SSW: 2.0 % of hours (1–2: 0.3%, 2–4: 0.8%, 4–6: 0.8%, 6–8: 0.1%, ≥8 m/s: 0%)Q1 · Jan–Mar – from SW: 2.6 % of hours (1–2: 0.4%, 2–4: 1.1%, 4–6: 1%, 6–8: 0.1%, ≥8 m/s: 0%)Q1 · Jan–Mar – from WSW: 3.9 % of hours (1–2: 0.3%, 2–4: 1.3%, 4–6: 2%, 6–8: 0.3%, ≥8 m/s: 0%)Q1 · Jan–Mar – from W: 11.0 % of hours (1–2: 0.6%, 2–4: 1.9%, 4–6: 3.7%, 6–8: 3%, ≥8 m/s: 1.8%)Q1 · Jan–Mar – from WNW: 19.6 % of hours (1–2: 0.6%, 2–4: 3%, 4–6: 4.5%, 6–8: 5.1%, ≥8 m/s: 6.4%)Q1 · Jan–Mar – from NW: 13.9 % of hours (1–2: 0.8%, 2–4: 2.8%, 4–6: 4.6%, 6–8: 3.8%, ≥8 m/s: 1.9%)Q1 · Jan–Mar – from NNW: 5.1 % of hours (1–2: 0.7%, 2–4: 2.2%, 4–6: 1.8%, 6–8: 0.4%, ≥8 m/s: 0%)Q1 · Jan–Marmean 4.6 m/s · calm 3.4 %12%24%NESWQ2 · Apr–Jun – from N: 1.8 % of hours (1–2: 0.7%, 2–4: 1%, 4–6: 0.1%, 6–8: 0%, ≥8 m/s: 0%)Q2 · Apr–Jun – from NNE: 1.4 % of hours (1–2: 0.6%, 2–4: 0.7%, 4–6: 0.1%, 6–8: 0%, ≥8 m/s: 0%)Q2 · Apr–Jun – from NE: 2.6 % of hours (1–2: 0.8%, 2–4: 1%, 4–6: 0.5%, 6–8: 0.2%, ≥8 m/s: 0.1%)Q2 · Apr–Jun – from ENE: 2.6 % of hours (1–2: 0.7%, 2–4: 1.4%, 4–6: 0.4%, 6–8: 0.1%, ≥8 m/s: 0%)Q2 · Apr–Jun – from E: 3.4 % of hours (1–2: 0.8%, 2–4: 2.1%, 4–6: 0.5%, 6–8: 0%, ≥8 m/s: 0%)Q2 · Apr–Jun – from ESE: 4.1 % of hours (1–2: 0.9%, 2–4: 2.4%, 4–6: 0.7%, 6–8: 0.1%, ≥8 m/s: 0%)Q2 · Apr–Jun – from SE: 3.5 % of hours (1–2: 0.8%, 2–4: 2%, 4–6: 0.6%, 6–8: 0.1%, ≥8 m/s: 0%)Q2 · Apr–Jun – from SSE: 3.0 % of hours (1–2: 0.8%, 2–4: 1.5%, 4–6: 0.6%, 6–8: 0.1%, ≥8 m/s: 0%)Q2 · Apr–Jun – from S: 2.6 % of hours (1–2: 0.7%, 2–4: 1%, 4–6: 0.7%, 6–8: 0.2%, ≥8 m/s: 0%)Q2 · Apr–Jun – from SSW: 2.9 % of hours (1–2: 0.6%, 2–4: 1.1%, 4–6: 1.1%, 6–8: 0.1%, ≥8 m/s: 0%)Q2 · Apr–Jun – from SW: 4.4 % of hours (1–2: 0.7%, 2–4: 1.5%, 4–6: 1.9%, 6–8: 0.3%, ≥8 m/s: 0%)Q2 · Apr–Jun – from WSW: 7.6 % of hours (1–2: 0.7%, 2–4: 1.8%, 4–6: 3.5%, 6–8: 1.5%, ≥8 m/s: 0.1%)Q2 · Apr–Jun – from W: 21.6 % of hours (1–2: 0.8%, 2–4: 2.8%, 4–6: 4.6%, 6–8: 6.7%, ≥8 m/s: 6.7%)Q2 · Apr–Jun – from WNW: 21.8 % of hours (1–2: 0.9%, 2–4: 3.1%, 4–6: 4.9%, 6–8: 5.4%, ≥8 m/s: 7.5%)Q2 · Apr–Jun – from NW: 9.4 % of hours (1–2: 0.8%, 2–4: 2.6%, 4–6: 3%, 6–8: 2.2%, ≥8 m/s: 0.8%)Q2 · Apr–Jun – from NNW: 2.5 % of hours (1–2: 0.7%, 2–4: 1.3%, 4–6: 0.4%, 6–8: 0.1%, ≥8 m/s: 0%)Q2 · Apr–Junmean 4.8 m/s · calm 4.6 %12%24%NESWQ3 · Jul–Sep – from N: 1.3 % of hours (1–2: 0.5%, 2–4: 0.7%, 4–6: 0.1%, 6–8: 0%, ≥8 m/s: 0%)Q3 · Jul–Sep – from NNE: 0.8 % of hours (1–2: 0.4%, 2–4: 0.4%, 4–6: 0%, 6–8: 0%, ≥8 m/s: 0%)Q3 · Jul–Sep – from NE: 1.3 % of hours (1–2: 0.6%, 2–4: 0.4%, 4–6: 0.2%, 6–8: 0.1%, ≥8 m/s: 0%)Q3 · Jul–Sep – from ENE: 1.2 % of hours (1–2: 0.5%, 2–4: 0.6%, 4–6: 0.1%, 6–8: 0%, ≥8 m/s: 0%)Q3 · Jul–Sep – from E: 2.2 % of hours (1–2: 0.7%, 2–4: 1.1%, 4–6: 0.4%, 6–8: 0%, ≥8 m/s: 0%)Q3 · Jul–Sep – from ESE: 3.1 % of hours (1–2: 0.6%, 2–4: 1.7%, 4–6: 0.7%, 6–8: 0.1%, ≥8 m/s: 0%)Q3 · Jul–Sep – from SE: 3.5 % of hours (1–2: 0.8%, 2–4: 1.7%, 4–6: 0.8%, 6–8: 0.2%, ≥8 m/s: 0%)Q3 · Jul–Sep – from SSE: 3.5 % of hours (1–2: 0.7%, 2–4: 1.4%, 4–6: 1%, 6–8: 0.3%, ≥8 m/s: 0.1%)Q3 · Jul–Sep – from S: 3.6 % of hours (1–2: 0.8%, 2–4: 1.4%, 4–6: 1.1%, 6–8: 0.3%, ≥8 m/s: 0%)Q3 · Jul–Sep – from SSW: 3.4 % of hours (1–2: 0.6%, 2–4: 1.4%, 4–6: 1.2%, 6–8: 0.2%, ≥8 m/s: 0%)Q3 · Jul–Sep – from SW: 5.3 % of hours (1–2: 0.8%, 2–4: 2%, 4–6: 2.2%, 6–8: 0.3%, ≥8 m/s: 0%)Q3 · Jul–Sep – from WSW: 8.5 % of hours (1–2: 0.8%, 2–4: 2.3%, 4–6: 3.3%, 6–8: 2%, ≥8 m/s: 0.1%)Q3 · Jul–Sep – from W: 24.0 % of hours (1–2: 1%, 2–4: 3.1%, 4–6: 5%, 6–8: 6.7%, ≥8 m/s: 8.2%)Q3 · Jul–Sep – from WNW: 21.9 % of hours (1–2: 0.9%, 2–4: 3.5%, 4–6: 4.7%, 6–8: 5.9%, ≥8 m/s: 6.9%)Q3 · Jul–Sep – from NW: 9.9 % of hours (1–2: 1%, 2–4: 2.9%, 4–6: 3%, 6–8: 2%, ≥8 m/s: 1%)Q3 · Jul–Sep – from NNW: 2.6 % of hours (1–2: 0.6%, 2–4: 1.4%, 4–6: 0.5%, 6–8: 0.1%, ≥8 m/s: 0%)Q3 · Jul–Sepmean 5.0 m/s · calm 3.9 %12%24%NESWQ4 · Oct–Dec – from N: 3.9 % of hours (1–2: 1%, 2–4: 2.5%, 4–6: 0.4%, 6–8: 0%, ≥8 m/s: 0%)Q4 · Oct–Dec – from NNE: 4.5 % of hours (1–2: 1%, 2–4: 2.7%, 4–6: 0.6%, 6–8: 0.1%, ≥8 m/s: 0.1%)Q4 · Oct–Dec – from NE: 11.1 % of hours (1–2: 1.3%, 2–4: 4.4%, 4–6: 2.8%, 6–8: 2%, ≥8 m/s: 0.6%)Q4 · Oct–Dec – from ENE: 7.4 % of hours (1–2: 1.3%, 2–4: 4.1%, 4–6: 1.5%, 6–8: 0.5%, ≥8 m/s: 0%)Q4 · Oct–Dec – from E: 5.7 % of hours (1–2: 1.1%, 2–4: 3.7%, 4–6: 0.8%, 6–8: 0.1%, ≥8 m/s: 0%)Q4 · Oct–Dec – from ESE: 3.7 % of hours (1–2: 0.8%, 2–4: 2.3%, 4–6: 0.6%, 6–8: 0%, ≥8 m/s: 0%)Q4 · Oct–Dec – from SE: 2.7 % of hours (1–2: 0.7%, 2–4: 1.6%, 4–6: 0.4%, 6–8: 0%, ≥8 m/s: 0%)Q4 · Oct–Dec – from SSE: 2.0 % of hours (1–2: 0.5%, 2–4: 1.2%, 4–6: 0.3%, 6–8: 0%, ≥8 m/s: 0%)Q4 · Oct–Dec – from S: 2.1 % of hours (1–2: 0.4%, 2–4: 1.1%, 4–6: 0.5%, 6–8: 0.1%, ≥8 m/s: 0%)Q4 · Oct–Dec – from SSW: 2.3 % of hours (1–2: 0.4%, 2–4: 1.1%, 4–6: 0.8%, 6–8: 0%, ≥8 m/s: 0%)Q4 · Oct–Dec – from SW: 3.2 % of hours (1–2: 0.3%, 2–4: 1.4%, 4–6: 1.4%, 6–8: 0.1%, ≥8 m/s: 0%)Q4 · Oct–Dec – from WSW: 4.6 % of hours (1–2: 0.3%, 2–4: 1.5%, 4–6: 2.5%, 6–8: 0.3%, ≥8 m/s: 0%)Q4 · Oct–Dec – from W: 10.0 % of hours (1–2: 0.5%, 2–4: 1.9%, 4–6: 4.4%, 6–8: 2.7%, ≥8 m/s: 0.5%)Q4 · Oct–Dec – from WNW: 16.0 % of hours (1–2: 0.6%, 2–4: 2.8%, 4–6: 5.7%, 6–8: 5.4%, ≥8 m/s: 1.5%)Q4 · Oct–Dec – from NW: 12.3 % of hours (1–2: 0.7%, 2–4: 3.7%, 4–6: 5.4%, 6–8: 2.2%, ≥8 m/s: 0.3%)Q4 · Oct–Dec – from NNW: 4.9 % of hours (1–2: 0.7%, 2–4: 2.9%, 4–6: 1.2%, 6–8: 0.1%, ≥8 m/s: 0%)Q4 · Oct–Decmean 4.0 m/s · calm 3.5 %
1–2 m/s2–44–66–8≥ 8 m/sDirection = where the wind blows from · % of hours
Wind by direction – table
FromQ1 % of hoursQ2 % of hoursQ3 % of hoursQ4 % of hours
N3.71.81.33.9
NNE4.71.40.84.5
NE10.92.61.311.1
ENE6.42.61.27.4
E4.73.42.25.7
ESE2.94.13.13.7
SE1.83.53.52.7
SSE1.53.03.52.0
S1.82.63.62.1
SSW2.02.93.42.3
SW2.64.45.33.2
WSW3.97.68.54.6
W11.021.624.010.0
WNW19.621.821.916.0
NW13.99.49.912.3
NNW5.12.52.64.9
Calm (< 1 m/s)3.44.63.93.5

A typical day in each quarter

Average temperature by hour of the day (ERA5 hourly 2015–2024, local time).

18°22°26°30°34°38°● Q3 32.5°● Q2 29.3°● Q4 25.9°● Q1 21.9°00:0003:0006:0009:0012:0015:0018:0021:0000:00 – Q1 21.4° · Q2 28.6° · Q3 31.9° · Q4 25.4°01:00 – Q1 20.8° · Q2 27.9° · Q3 31.3° · Q4 24.8°02:00 – Q1 20.3° · Q2 27.3° · Q3 30.8° · Q4 24.3°03:00 – Q1 20.4° · Q2 27.1° · Q3 30.5° · Q4 24.4°04:00 – Q1 19.9° · Q2 26.6° · Q3 30.1° · Q4 23.9°05:00 – Q1 19.5° · Q2 26.2° · Q3 29.7° · Q4 23.5°06:00 – Q1 19.1° · Q2 25.9° · Q3 29.3° · Q4 23.1°07:00 – Q1 18.8° · Q2 26.9° · Q3 29.8° · Q4 23°08:00 – Q1 20.1° · Q2 28.9° · Q3 31.4° · Q4 24.5°09:00 – Q1 22.2° · Q2 30.7° · Q3 33° · Q4 26.6°10:00 – Q1 24.1° · Q2 32.2° · Q3 34.5° · Q4 28.4°11:00 – Q1 25.5° · Q2 33° · Q3 35.4° · Q4 29.6°12:00 – Q1 26.4° · Q2 33.4° · Q3 35.8° · Q4 30.3°13:00 – Q1 26.9° · Q2 33.4° · Q3 35.9° · Q4 30.6°14:00 – Q1 27° · Q2 33.3° · Q3 35.9° · Q4 30.7°15:00 – Q1 26.5° · Q2 32.7° · Q3 35.4° · Q4 30.3°16:00 – Q1 26.4° · Q2 32.6° · Q3 35.3° · Q4 30.1°17:00 – Q1 25.7° · Q2 32.1° · Q3 34.7° · Q4 29.3°18:00 – Q1 24.8° · Q2 31.3° · Q3 34° · Q4 28.4°19:00 – Q1 24° · Q2 30.5° · Q3 33.4° · Q4 27.9°20:00 – Q1 23.5° · Q2 30.3° · Q3 33.3° · Q4 27.5°21:00 – Q1 23° · Q2 30.1° · Q3 33.2° · Q4 27°22:00 – Q1 22.5° · Q2 29.8° · Q3 32.9° · Q4 26.4°23:00 – Q1 21.9° · Q2 29.3° · Q3 32.5° · Q4 25.9°

Average wind speed by hour – the afternoon sea breeze peaks at 15:00–17:00 in every quarter.

23456789● Q1 4.4● Q3 4.4● Q2 4.2● Q4 3.600:0003:0006:0009:0012:0015:0018:0021:0000:00 – Q1 4.1 · Q2 3.8 · Q3 4 · Q4 3.301:00 – Q1 3.8 · Q2 3.4 · Q3 3.8 · Q4 3.202:00 – Q1 3.7 · Q2 3.2 · Q3 3.6 · Q4 3.103:00 – Q1 3.7 · Q2 3.2 · Q3 3.5 · Q4 3.104:00 – Q1 3.7 · Q2 3.2 · Q3 3.4 · Q4 3.205:00 – Q1 3.7 · Q2 3.1 · Q3 3.2 · Q4 3.306:00 – Q1 3.7 · Q2 3 · Q3 3 · Q4 3.407:00 – Q1 3.8 · Q2 2.8 · Q3 2.8 · Q4 3.508:00 – Q1 3.7 · Q2 2.6 · Q3 2.7 · Q4 3.309:00 – Q1 3.5 · Q2 2.8 · Q3 2.8 · Q4 3.210:00 – Q1 3.5 · Q2 3.5 · Q3 3.4 · Q4 311:00 – Q1 3.7 · Q2 4.5 · Q3 4.5 · Q4 3.112:00 – Q1 4.1 · Q2 5.7 · Q3 5.7 · Q4 3.613:00 – Q1 4.9 · Q2 6.7 · Q3 6.7 · Q4 4.214:00 – Q1 5.6 · Q2 7.4 · Q3 7.5 · Q4 4.915:00 – Q1 6 · Q2 7.6 · Q3 7.8 · Q4 5.216:00 – Q1 6.5 · Q2 7.7 · Q3 8 · Q4 5.617:00 – Q1 6.6 · Q2 7.7 · Q3 7.9 · Q4 5.718:00 – Q1 6.4 · Q2 7.3 · Q3 7.5 · Q4 5.619:00 – Q1 6.1 · Q2 6.7 · Q3 6.9 · Q4 5.420:00 – Q1 5.8 · Q2 6.1 · Q3 6.3 · Q4 521:00 – Q1 5.3 · Q2 5.4 · Q3 5.5 · Q4 4.522:00 – Q1 4.9 · Q2 4.7 · Q3 4.9 · Q4 423:00 – Q1 4.4 · Q2 4.2 · Q3 4.4 · Q4 3.6

m/s at 10 m

Sun and solar energy

Daily global horizontal irradiation by month (ERA5 1991–2020) – the resource behind the roof PV and the PV carports. Annual ≈ 2,263 kWh/m².

02468Jan: 4.5 kWh/m² per day · sunshine 10.4 h of 10.8 h daylight4.5JanFeb: 5.4 kWh/m² per day · sunshine 10.7 h of 11.4 h daylight5.4FebMar: 6.4 kWh/m² per day · sunshine 11 h of 12 h daylight6.4MarApr: 7.3 kWh/m² per day · sunshine 12.1 h of 12.7 h daylight7.3AprMay: 7.6 kWh/m² per day · sunshine 12.7 h of 13.3 h daylight7.6MayJun: 7.6 kWh/m² per day · sunshine 13 h of 13.6 h daylight7.6JunJul: 7.3 kWh/m² per day · sunshine 12.9 h of 13.5 h daylight7.3JulAug: 7.0 kWh/m² per day · sunshine 12.3 h of 12.9 h daylight7.0AugSep: 6.4 kWh/m² per day · sunshine 11.2 h of 12.3 h daylight6.4SepOct: 5.6 kWh/m² per day · sunshine 10.9 h of 11.6 h daylight5.6OctNov: 4.8 kWh/m² per day · sunshine 10.3 h of 11 h daylight4.8NovDec: 4.3 kWh/m² per day · sunshine 10.3 h of 10.7 h daylight4.3DeckWh/m² per day

Sunshine: 10.3–13.0 hours a day; direct sunshine on about 95 % of daylight hours (ERA5). Forma: 9+ hours of direct sun on the site and roofs on 21 June; sunset always over the sea (azimuth 242°–293°).

Prediction – the warming trend to 2030

Quarterly mean temperature 1991–2024 (ERA5, thin lines), linear trend (dashed) and the value projected for 2030, the first years of operation. Hover a point for the year.

20°24°28°32°36°projectionQ1 1991: mean 22.34 °CQ1 1992: mean 19.82 °CQ1 1993: mean 21.37 °CQ1 1994: mean 22.67 °CQ1 1995: mean 22.5 °CQ1 1996: mean 22.44 °CQ1 1997: mean 21.21 °CQ1 1998: mean 21.65 °CQ1 1999: mean 23.68 °CQ1 2000: mean 22.21 °CQ1 2001: mean 22.78 °CQ1 2002: mean 22.79 °CQ1 2003: mean 22.12 °CQ1 2004: mean 23.02 °CQ1 2005: mean 22.24 °CQ1 2006: mean 23.43 °CQ1 2007: mean 22.13 °CQ1 2008: mean 22.96 °CQ1 2009: mean 23.26 °CQ1 2010: mean 24.09 °CQ1 2011: mean 23 °CQ1 2012: mean 22.14 °CQ1 2013: mean 24.02 °CQ1 2014: mean 23.56 °CQ1 2015: mean 23.53 °CQ1 2016: mean 23.61 °CQ1 2017: mean 22.54 °CQ1 2018: mean 23.71 °CQ1 2019: mean 22.05 °CQ1 2020: mean 21.53 °CQ1 2021: mean 23.84 °CQ1 2022: mean 21.97 °CQ1 2023: mean 22.84 °CQ1 2024: mean 23.63 °CQ2 1991: mean 29.72 °CQ2 1992: mean 27.49 °CQ2 1993: mean 28.44 °CQ2 1994: mean 29.12 °CQ2 1995: mean 28.58 °CQ2 1996: mean 28.7 °CQ2 1997: mean 27.86 °CQ2 1998: mean 28.71 °CQ2 1999: mean 29.54 °CQ2 2000: mean 28.95 °CQ2 2001: mean 28.86 °CQ2 2002: mean 28.27 °CQ2 2003: mean 29.32 °CQ2 2004: mean 29.03 °CQ2 2005: mean 29.17 °CQ2 2006: mean 29.12 °CQ2 2007: mean 28.3 °CQ2 2008: mean 29.11 °CQ2 2009: mean 28.72 °CQ2 2010: mean 29.73 °CQ2 2011: mean 28.44 °CQ2 2012: mean 29.47 °CQ2 2013: mean 29.42 °CQ2 2014: mean 29.98 °CQ2 2015: mean 28.79 °CQ2 2016: mean 30.29 °CQ2 2017: mean 30.41 °CQ2 2018: mean 30.22 °CQ2 2019: mean 30.02 °CQ2 2020: mean 29 °CQ2 2021: mean 30.67 °CQ2 2022: mean 30.29 °CQ2 2023: mean 29.63 °CQ2 2024: mean 30.48 °CQ3 1991: mean 30.03 °CQ3 1992: mean 30.79 °CQ3 1993: mean 31.77 °CQ3 1994: mean 31.3 °CQ3 1995: mean 31.43 °CQ3 1996: mean 31.86 °CQ3 1997: mean 31.23 °CQ3 1998: mean 32.18 °CQ3 1999: mean 31.64 °CQ3 2000: mean 31.27 °CQ3 2001: mean 31.7 °CQ3 2002: mean 31.85 °CQ3 2003: mean 31.79 °CQ3 2004: mean 31.73 °CQ3 2005: mean 31.63 °CQ3 2006: mean 31.83 °CQ3 2007: mean 31.75 °CQ3 2008: mean 31.58 °CQ3 2009: mean 31.46 °CQ3 2010: mean 32.46 °CQ3 2011: mean 31.27 °CQ3 2012: mean 31.73 °CQ3 2013: mean 31.71 °CQ3 2014: mean 31.96 °CQ3 2015: mean 32.93 °CQ3 2016: mean 32.16 °CQ3 2017: mean 33.53 °CQ3 2018: mean 32.55 °CQ3 2019: mean 32.36 °CQ3 2020: mean 32.56 °CQ3 2021: mean 32.91 °CQ3 2022: mean 32.42 °CQ3 2023: mean 33.61 °CQ3 2024: mean 33.85 °CQ4 1991: mean 25.28 °CQ4 1992: mean 25.15 °CQ4 1993: mean 26.95 °CQ4 1994: mean 25.7 °CQ4 1995: mean 25.98 °CQ4 1996: mean 26.35 °CQ4 1997: mean 25.56 °CQ4 1998: mean 27.27 °CQ4 1999: mean 27.25 °CQ4 2000: mean 25.43 °CQ4 2001: mean 26.88 °CQ4 2002: mean 26.24 °CQ4 2003: mean 26.78 °CQ4 2004: mean 26.55 °CQ4 2005: mean 26.86 °CQ4 2006: mean 25.83 °CQ4 2007: mean 26.94 °CQ4 2008: mean 26.71 °CQ4 2009: mean 26.3 °CQ4 2010: mean 28.19 °CQ4 2011: mean 25.88 °CQ4 2012: mean 26.51 °CQ4 2013: mean 26.12 °CQ4 2014: mean 26.86 °CQ4 2015: mean 26.49 °CQ4 2016: mean 27 °CQ4 2017: mean 26.7 °CQ4 2018: mean 25.83 °CQ4 2019: mean 26.75 °CQ4 2020: mean 27.18 °CQ4 2021: mean 26.94 °CQ4 2022: mean 26.71 °CQ4 2023: mean 28.2 °CQ4 2024: mean 27.02 °C● Q3 33.4° +0.62/dec● Q2 30.4° +0.53/dec● Q4 27.3° +0.34/dec● Q1 23.6° +0.42/dec19912000201020202030
QuarterWarming °C / decade (1991–2024)Mean max °C: normal → 2030Mean °C: normal → 2030Mean min °C: normal → 2030Mean max 2050 (trend)Nights ≥ 28 °C: 1991–2020 → 2015–24 → 2030
Q1 · Jan–Mar+0.42 ± 0.1529.3 → 30.922.3 → 23.415.7 → 16.432.10 → 0 → 0
Q2 · Apr–Jun+0.53 ± 0.1038.0 → 39.630.6 → 31.923.5 → 24.641.010 → 20 → 24
Q3 · Jul–Sep+0.62 ± 0.0940.5 → 42.133.4 → 34.927.1 → 28.843.440 → 65 → 77
Q4 · Oct–Dec+0.34 ± 0.1133.3 → 34.726.3 → 27.119.9 → 20.635.72 → 4 → 4

Method: least-squares linear trend of each quarter's ERA5 mean, maximum and minimum temperature, 1991–2024 (± one standard error). The 2030 values add that trend to the 1991–2020 station normals (centred on 2005). This is a statistical extrapolation of the observed trend, not a climate-model scenario.

How it fits the Forma site analysis

StudyAutodesk Forma (presentation p. 17–23)Climate data (this page)Agreement
Sun9+ hours of direct sun on site and roofs, 21 June13.0 h sunshine a day in June; solar peak 7.6 kWh/m²·day✓ consistent
SunsetAzimuth 242° (Dec) to 293° (Jun), always over the seaAfternoon solar gain on the west facade in every quarter✓ consistent
Wind directionRoof terraces exposed to the W–NW breezeWSW–NW = 43–64 % of hours, strongest Q2–Q3✓ consistent
Wind comfortNEN 8100 / Lawson: 0 % uncomfortable at gradeMean 4–5 m/s; ≥ 8 m/s only 3–16 % of hours, from the W–NW, in the afternoon✓ consistent – screens on the W–NW roof edges
Solar resource≈ 2,000 kWh/m²·yr on the roofs≈ 2,263 kWh/m²·yr horizontal✓ consistent

Sources and data

  • Yanbu station (WMO 40439) – climate normals 1991–2020, World Meteorological Organization; humidity Deutscher Wetterdienst (as published in the Yanbu climate table on Wikipedia).
  • ERA5 reanalysis – ECMWF / Copernicus Climate Change Service, via the Open-Meteo historical weather API; grid cell 24.01 °N 38.18 °E (2 m), next to the site: 12,419 daily records 1991–2024 and 87,672 hourly records 2015–2024. The grid cell is partly over the sea, so its afternoon maxima run 2–5 °C below the airport station – it represents the waterfront exposure; the station is the official temperature reference.
  • Autodesk Forma site studies – sun hours, shadows, daylight, pedestrian wind comfort (NEN 8100 / Lawson), solar – RC presentation REV09 pages 17–23.
Climate data workbook (Excel)Climate analysis boards (PDF)
Main site