Days 1-16 are a real forecast from global weather models. Days 17-30 are season-typical values based on DWD climate normals 1991-2020 — good for planning, NOT an exact forecast that far ahead.
30 days — Köln
14 real + 16 synthesised
Wed · Today Clear
+33°+20°3%
Thu · Tomorrow Clear
+27°+16°1%
Friday 7/8 Clear
+25°+13°1%
Saturday 8/8 Clear
+29°+14°1%
Sunday 9/8 Clear
+36°+17°1%
Monday 10/8 Clear
+33°+19°1%
Tuesday 11/8 Clear
+27°+14°1%
Wednesday 12/8 Clear
+31°+14°1%
Thursday 13/8 Clear
+34°+16°1%
Friday 14/8 Partly cloudy
+32°+24°3%
Saturday 15/8 Partly cloudy
+35°+22°2%
Sunday 16/8 Partly cloudy
+24°+19°2,1 mm
Monday 17/8 Clear
+32°+17°2%
Tuesday 18/8 Partly cloudy
+27°+18°11%
Wednesday 19/8 Showers
+25°+15°1,6 mm
Thursday 20/8 Rain
+25°+15°0,7 mm
Friday 21/8 Partly cloudy (climate normal)
+26°+15°20%
Saturday 22/8 Rain (climate normal)
+26°+15°7,6 mm
Sunday 23/8 Partly cloudy (climate normal)
+23°+13°20%
Monday 24/8 Partly cloudy (climate normal)
+22°+13°20%
Tuesday 25/8 Rain (climate normal)
+22°+13°7,6 mm
Wednesday 26/8 Partly cloudy (climate normal)
+24°+14°20%
Thursday 27/8 Partly cloudy (climate normal)
+25°+14°20%
Friday 28/8 Rain (climate normal)
+25°+15°9,2 mm
Saturday 29/8 Partly cloudy (climate normal)
+25°+15°20%
Sunday 30/8 Partly cloudy (climate normal)
+21°+12°20%
Monday 31/8 Rain (climate normal)
+21°+12°5,9 mm
Tuesday 1/9 Partly cloudy (climate normal)
+17°+9°20%
Wednesday 2/9 Partly cloudy (climate normal)
+19°+10°20%
Thursday 3/9 Rain (climate normal)
+21°+12°6,3 mm
Long-range forecast · Köln
Köln — 30-day analysis
Across the 30-day trend for Köln, highs and lows span 9° to 36°, cooling down later in the month. The first 16 days are a real forecast, with rain on about 2 of them; the rest is based on the 1991–2020 climate normals.
How does the long-range forecast work?
Days 1-16 are a real forecast from global models (ICON, ECMWF, GFS): days 1-3 are almost always right, uncertainty grows afterwards, and from day 11 these are tendencies rather than exact values.
From day 17 a serious day-by-day forecast is physically impossible. We therefore show the 1991-2020 climate normals (monthly mean Tmax/Tmin) directly for Köln, with mild weekly variation — the typical weather for the season, not a daily prediction.
Rule of thumb: good for “how warm is it usually in late July?”, not for “will it rain on the 27th?”.