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