Days 1-14 are a real forecast from global weather models. Days 15-30 are season-typical values based on SMHI climate normals 1991-2020 — good for planning, NOT an exact forecast that far ahead.
30 days — Norrköping
14 real + 16 synthesised
Wed · Today Partly cloudy
+24°+13°2,5 mm
Thu · Tomorrow Partly cloudy
+25°+15°0,1 mm
Friday 7/8 Showers
+24°+15°0,4 mm
Saturday 8/8 Partly cloudy
+22°+11°11%
Sunday 9/8 Partly cloudy
+26°+11°17%
Monday 10/8 Partly cloudy
+22°+14°0,9 mm
Tuesday 11/8 Clear
+21°+9°3%
Wednesday 12/8 Clear
+22°+7°2%
Thursday 13/8 Clear
+23°+10°4%
Friday 14/8 Showers
+15°+13°1,1 mm
Saturday 15/8 Fog
+18°+13°2,8 mm
Sunday 16/8 Drizzle
+20°+12°21,3 mm
Monday 17/8 Showers
+22°+13°2,6 mm
Tuesday 18/8 Clear
+22°+13°0,3 mm
Wednesday 19/8 Rain (climate normal)
+22°+12°6,6 mm
Thursday 20/8 Partly cloudy (climate normal)
+25°+14°20%
Friday 21/8 Partly cloudy (climate normal)
+24°+14°20%
Saturday 22/8 Rain (climate normal)
+23°+13°3,5 mm
Sunday 23/8 Partly cloudy (climate normal)
+21°+12°20%
Monday 24/8 Partly cloudy (climate normal)
+22°+12°20%
Tuesday 25/8 Rain (climate normal)
+20°+11°7,3 mm
Wednesday 26/8 Partly cloudy (climate normal)
+22°+12°20%
Thursday 27/8 Partly cloudy (climate normal)
+24°+14°20%
Friday 28/8 Rain (climate normal)
+26°+15°8,6 mm
Saturday 29/8 Partly cloudy (climate normal)
+25°+14°20%
Sunday 30/8 Partly cloudy (climate normal)
+22°+12°20%
Monday 31/8 Rain (climate normal)
+19°+11°4,6 mm
Tuesday 1/9 Partly cloudy (climate normal)
+16°+7°20%
Wednesday 2/9 Partly cloudy (climate normal)
+18°+9°20%
Thursday 3/9 Rain (climate normal)
+19°+9°5,9 mm
How does the long-range forecast work?
Days 1-14: Fetched live from global weather models (ECMWF, GFS) with statistical correction. Reliability ~85% for days 1-3, ~60% for days 7-10, ~45% for days 11-14.
Days 15-30: 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 SMHI climate normals 1991-2020 (Stockholm baseline with latitude correction for Norrköping), with mild weekly variation.
Use: "Roughly how warm is it usually in Stockholm in the last week of July?" — a good question for days 15-30. "Will it rain on 27 May?" — no serious forecast can say.