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 — Bonn
14 real + 16 synthesised
Sat · Today Rain
+31°+18°7,3 mm
Sun · Tomorrow Showers
+33°+18°3,4 mm
Monday 22/6 Showers
+33°+18°3,3 mm
Tuesday 23/6 Partly cloudy
+32°+17°0,2 mm
Wednesday 24/6 Clear
+34°+19°3%
Thursday 25/6 Clear
+28°+17°3%
Friday 26/6 Partly cloudy
+29°+12°4%
Saturday 27/6 Showers
+31°+16°1,3 mm
Sunday 28/6 Showers
+28°+16°2,3 mm
Monday 29/6 Partly cloudy
+24°+10°17%
Tuesday 30/6 Showers
+19°+11°3,2 mm
Wednesday 1/7 Showers
+17°+12°1,2 mm
Thursday 2/7 Partly cloudy
+21°+9°5%
Friday 3/7 Clear
+25°+12°2%
Saturday 4/7 Showers
+25°+14°1,8 mm
Sunday 5/7 Showers
+24°+14°2,3 mm
Monday 6/7 Partly cloudy (climate normal)
+29°+16°20%
Tuesday 7/7 Rain (climate normal)
+27°+15°8,9 mm
Wednesday 8/7 Partly cloudy (climate normal)
+23°+13°20%
Thursday 9/7 Partly cloudy (climate normal)
+24°+13°20%
Friday 10/7 Rain (climate normal)
+24°+13°5,7 mm
Saturday 11/7 Partly cloudy (climate normal)
+24°+13°20%
Sunday 12/7 Partly cloudy (climate normal)
+28°+16°20%
Monday 13/7 Rain (climate normal)
+27°+15°8,6 mm
Tuesday 14/7 Partly cloudy (climate normal)
+26°+15°20%
Wednesday 15/7 Partly cloudy (climate normal)
+25°+14°20%
Thursday 16/7 Rain (climate normal)
+21°+12°6,3 mm
Friday 17/7 Partly cloudy (climate normal)
+23°+13°20%
Saturday 18/7 Partly cloudy (climate normal)
+24°+14°20%
Sunday 19/7 Rain (climate normal)
+26°+15°9,7 mm
How does the long-range forecast work?
Days 1-16: Fetched live from global weather models (ECMWF, GFS, ICON) with statistical correction. Reliability ~85% for days 1-3, ~60% for days 7-10, ~45% for days 11-16.
Days 17-30: A real forecast does not exist that far ahead (a chaotic system). Instead we show season-typical values: the month’s average Tmax/Tmin from DWD climate normals 1991-2020 directly for Bonn, with mild weekly variation.
Use: "Roughly how warm is it usually in Berlin in the last week of July?" — a good question for days 17-30. "Will it rain on 27 May?" — no serious forecast can say.