Grimselsee

Grimselsee
Lake Grimsel
Grimselsee ; Lake Grimsel
	Grimselsee ; Lake Grimsel Grimselsee ; Lake Grimsel Grimselsee ; Lake Grimsel
	map
Location	Guttannen, Canton of Bern
Coordinates	46°34′10.52″N 8°19′38.66″E
Type	artificial lake, hydroelectric reservoir
Primary inflows	Oberaarbach [de], Treibtenbach
Primary outflows	Aare
Catchment area	74.4 km2 (28.7 sq mi)
Basin countries	Switzerland
Surface area	2.63 km2 (1.02 sq mi)
Water volume	95 million cubic metres (77,000 acre⋅ft)
Surface elevation	1,908 m (6,260 ft)

The Grimselsee or Lake Grimsel is an artificial lake near the Grimsel Pass in the Canton of Bern, Switzerland. With a volume of 95 mio m³ (20.9 billion imperial gallons, 20.1 billion US gallons), it is larger than other hydroelectric reservoirs in the Aare headwaters region: Oberaarsee, Räterichsbodensee and Gelmersee. The dam was completed in 1932 and is operated by Kraftwerke Oberhasli AG (KWO). It is located in the municipality of Guttannen.

Lake Grimsel and Räterichsbodensee in the background.

Quick facts Grimselsee Lake Grimsel, Location ...

Climate data for Grimselsee (Grimsel Hospiz), elevation 1,980 m (6,500 ft), (1991–2020)
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Mean daily maximum °C (°F)	−1.8 (28.8)	−2.0 (28.4)	0.3 (32.5)	3.0 (37.4)	7.3 (45.1)	11.4 (52.5)	13.2 (55.8)	13.3 (55.9)	9.7 (49.5)	6.8 (44.2)	1.7 (35.1)	−0.9 (30.4)	5.2 (41.4)
Daily mean °C (°F)	−4.5 (23.9)	−4.9 (23.2)	−2.6 (27.3)	0.2 (32.4)	4.3 (39.7)	8.2 (46.8)	10.2 (50.4)	10.3 (50.5)	6.9 (44.4)	4.0 (39.2)	−0.7 (30.7)	−3.5 (25.7)	2.3 (36.1)
Mean daily minimum °C (°F)	−7.4 (18.7)	−7.9 (17.8)	−5.5 (22.1)	−2.7 (27.1)	1.3 (34.3)	4.9 (40.8)	7.0 (44.6)	7.3 (45.1)	4.2 (39.6)	1.4 (34.5)	−3.1 (26.4)	−6.2 (20.8)	−0.6 (30.9)
Average precipitation mm (inches)	190.1 (7.48)	163.2 (6.43)	169.1 (6.66)	150.2 (5.91)	158.6 (6.24)	127.3 (5.01)	126.3 (4.97)	139.4 (5.49)	128.6 (5.06)	129.3 (5.09)	167.8 (6.61)	184.1 (7.25)	1,834 (72.20)
Average snowfall cm (inches)	203.9 (80.3)	192.7 (75.9)	202.3 (79.6)	151.4 (59.6)	74.9 (29.5)	21.7 (8.5)	3.3 (1.3)	5.2 (2.0)	21.3 (8.4)	53.8 (21.2)	149.5 (58.9)	179.6 (70.7)	1,259.6 (495.9)
Average precipitation days (≥ 1.0 mm)	12.1	11.8	13.2	12.5	13.9	14.6	13.4	13.8	11.3	10.8	11.6	12.7	151.7
Average relative humidity (%)	65.9	68.2	73.1	75.6	74.6	76.1	75.3	75.8	75.6	70.0	71.3	66.6	72.3
Mean monthly sunshine hours	71.6	95.2	128.7	123.0	135.3	185.2	177.7	169.1	139.8	114.9	64.1	57.0	1,434.6
Source: NOAA^[1]

Climate