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 — Umeå
14 real + 16 synthesised
Wed · Today Showers
+13°+11°3,7 mm
Thu · Tomorrow Fog
+16°+12°14,7 mm
Friday 7/8 Showers
+19°+11°4,1 mm
Saturday 8/8 Clear
+17°+9°9%
Sunday 9/8 Clear
+20°+11°3,0 mm
Monday 10/8 Cloudy
+18°+11°13%
Tuesday 11/8 Partly cloudy
+18°+9°0,9 mm
Wednesday 12/8 Clear
+18°+11°6%
Thursday 13/8 Partly cloudy
+15°+8°17%
Friday 14/8 Clear
+16°+6°6%
Saturday 15/8 Partly cloudy
+14°+7°11%
Sunday 16/8 Partly cloudy
+16°+12°25%
Monday 17/8 Partly cloudy
+17°+12°6,4 mm
Tuesday 18/8 Showers
+16°+13°11,3 mm
Wednesday 19/8 Rain (climate normal)
+18°+11°4,0 mm
Thursday 20/8 Partly cloudy (climate normal)
+20°+12°20%
Friday 21/8 Partly cloudy (climate normal)
+20°+12°20%
Saturday 22/8 Rain (climate normal)
+20°+12°4,3 mm
Sunday 23/8 Partly cloudy (climate normal)
+17°+10°20%
Monday 24/8 Partly cloudy (climate normal)
+16°+10°20%
Tuesday 25/8 Rain (climate normal)
+15°+9°4,8 mm
Wednesday 26/8 Partly cloudy (climate normal)
+18°+11°20%
Thursday 27/8 Partly cloudy (climate normal)
+20°+12°20%
Friday 28/8 Rain (climate normal)
+19°+12°6,0 mm
Saturday 29/8 Partly cloudy (climate normal)
+18°+11°20%
Sunday 30/8 Partly cloudy (climate normal)
+16°+10°20%
Monday 31/8 Rain (climate normal)
+16°+10°7,8 mm
Tuesday 1/9 Partly cloudy (climate normal)
+10°+4°20%
Wednesday 2/9 Partly cloudy (climate normal)
+12°+5°20%
Thursday 3/9 Rain (climate normal)
+14°+7°4,8 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 directly for Umeå, 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.