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