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