Days 1-14 are a real forecast from global weather models. Days 15-30 are season-typical values based on climate normals 1991-2020 (MET) — good for planning, NOT an exact forecast that far ahead.
30 days — Fredrikstad
14 real + 16 synthesised
Mon · Today Clear
+22°+10°3%
Tue · Tomorrow Partly cloudy
+21°+12°6%
Wednesday 22/7 Partly cloudy
+21°+13°0,1 mm
Thursday 23/7 Clear
+21°+10°4%
Friday 24/7 Clear
+22°+15°1,4 mm
Saturday 25/7 Partly cloudy
+20°+13°13%
Sunday 26/7 Showers
+19°+14°3,2 mm
Monday 27/7 Partly cloudy
+26°+12°0,5 mm
Tuesday 28/7 Partly cloudy
+24°+15°23%
Wednesday 29/7 Partly cloudy
+21°+16°13%
Thursday 30/7 Clear
+20°+13°3%
Friday 31/7 Partly cloudy
+17°+14°9%
Saturday 1/8 Partly cloudy
+17°+12°9%
Sunday 2/8 Showers
+17°+13°9,1 mm
Monday 3/8 Rain (climate normal)
+20°+11°8,0 mm
Tuesday 4/8 Partly cloudy (climate normal)
+23°+13°20%
Wednesday 5/8 Partly cloudy (climate normal)
+22°+12°20%
Thursday 6/8 Rain (climate normal)
+21°+12°6,2 mm
Friday 7/8 Partly cloudy (climate normal)
+20°+12°20%
Saturday 8/8 Partly cloudy (climate normal)
+18°+10°20%
Sunday 9/8 Rain (climate normal)
+17°+10°4,5 mm
Monday 10/8 Partly cloudy (climate normal)
+20°+11°20%
Tuesday 11/8 Partly cloudy (climate normal)
+22°+12°20%
Wednesday 12/8 Rain (climate normal)
+23°+13°4,7 mm
Thursday 13/8 Partly cloudy (climate normal)
+21°+12°20%
Friday 14/8 Partly cloudy (climate normal)
+19°+10°20%
Saturday 15/8 Rain (climate normal)
+17°+10°11,3 mm
Sunday 16/8 Partly cloudy (climate normal)
+17°+10°20%
Monday 17/8 Partly cloudy (climate normal)
+20°+11°20%
Tuesday 18/8 Rain (climate normal)
+23°+13°9,2 mm
How does the long-range forecast work?
Days 1-14: Fetched live from global weather models (ECMWF, GFS) with statistical correction. Reliability about 85 % for days 1-3, about 60 % for days 7-10, about 45 % for days 11-14.
Days 15-30: A real forecast does not exist that far ahead (chaotic system). Instead we show season-typical values: the monthly average Tmax/Tmin from climate normals 1991-2020, with mild weekly variation.
Use: «About how warm is it usually in Oslo the last week of July?» — a good question for days 15-30. «Will it rain on 27 May?» — no serious forecast can answer that.