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Weather & Climate in Mosfellsbær, Iceland
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Mosfellsbær has a cool climate with an average annual temperature of 37°F (3°C). Winters average 30°F in January while summers reach 49°F in July / relatively mild seasonal variation. The area gets 259 sunny days per year, above the national average. Annual precipitation totals 42.2 inches. The area receives 23.5 inches of snow annually, a moderate snowfall amount. The city sits at an elevation of 72 feet.
Temperature
30°F Jan (-1°C)
49°F Jul (9°C)
| Annual Average | 37.4°F |
| 31% below US avg | |
| January Average | 30°F (-1°C) |
| July Average | 49°F (9°C) |
| Sunny Days | 259 days/yr |
Geography
| Elevation | 72 ft (22 m) |
| Area | 77.0 sq mi (199.5 km²) |
| Population Density | 157/sq mi |
| Coordinates | 64.1667°N, 21.7000°W |
| Timezone | Atlantic/Reykjavik |
Precipitation & Snow
Air Quality
Earthquake History
167 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M6.5.
| Jun 21, 2000 | 12 km ENE of Selfoss, Iceland | M6.5 | 50 km | 10 km |
| Jun 17, 2000 | 25 km E of Selfoss, Iceland | M6.5 | 63 km | 10 km |
| May 29, 2008 | 8 km N of Selfoss, Iceland | M6.3 | 38 km | 9 km |
| Jun 17, 2000 | 18 km E of Selfoss, Iceland | M5.7 | 57 km | 10 km |
| Feb 24, 2021 | 6 km SE of Vogar, Iceland | M5.6 | 37 km | 10 km |
| Jul 31, 2022 | 3 km SSE of Vogar, Iceland | M5.4 | 39 km | 10 km |
| Jun 4, 1998 | 5 km W of Hveragerði, Iceland | M5.4 | 28 km | 10 km |
| Mar 7, 2021 | 11 km ENE of Vogar, Iceland | M5.3 | 28 km | 10 km |
| Mar 14, 2021 | 9 km SW of Álftanes, Iceland | M5.3 | 26 km | 10 km |
| Apr 1, 2025 | 6 km NW of Grindavík, Iceland | M5.2 | 50 km | 10 km |
| Aug 23, 2003 | 9 km SE of Vogar, Iceland | M5.2 | 39 km | 10 km |
| Feb 27, 2021 | 8 km SW of Álftanes, Iceland | M5.2 | 26 km | 10 km |
| Jul 9, 2023 | 9 km SW of Álftanes, Iceland | M5.2 | 26 km | 5 km |
| Jan 30, 1991 | 47 km NNE of Hveragerði, Iceland | M5.2 | 50 km | 10 km |
| Mar 10, 2021 | 9 km SW of Álftanes, Iceland | M5.1 | 26 km | 10 km |
| Nov 13, 1998 | 10 km WNW of Þorlákshöfn, Iceland | M5.1 | 32 km | 10 km |
| Aug 2, 2022 | 1 km SSE of Hafnarfjörður, Iceland | M5.0 | 17 km | 10 km |
| Feb 27, 2007 | 95 km SW of Grindavík, Iceland | M5.0 | 146 km | 10 km |
| Apr 1, 2025 | 9 km WNW of Grindavík, Iceland | M4.9 | 57 km | 4 km |
| Jun 17, 2000 | 9 km ENE of Vogar, Iceland | M4.9 | 30 km | 10 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tsunami History
1 tsunami recorded within 500 km. Highest wave on record: 75.0 m (246 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1967 | ICELAND: CENTRAL-SOUTH | Meteorological | 75.0 m | — | 118 km |
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
15 volcanoes within 200 km. Closest: Hengill (17 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Hengill | Crater rows | 803 m (2,635 ft) | 150 | 17 km |
| Hromundartindur | Stratovolcano | 550 m (1,804 ft) | Unknown | 20 km |
| Brennisteinsfjoll | Crater rows | 610 m (2,001 ft) | 1341 | 26 km |
| Krysuvik | Crater rows | 360 m (1,181 ft) | 1340 | 37 km |
| Grimsnes | Crater rows | 200 m (656 ft) | -3500 | 42 km |
| Reykjanes | Crater rows | 140 m (459 ft) | 1831 | 55 km |
| Prestahnukur | Subglacial | 1,385 m (4,544 ft) | -3350 | 68 km |
| Ljosufjoll | Fissure vent(s) | 1,063 m (3,488 ft) | 960 | 90 km |
| Hekla | Stratovolcano | 1,490 m (4,888 ft) | 2000 | 101 km |
| Tindfjallajokull | Stratovolcano | 1,464 m (4,803 ft) | Unknown | 106 km |
| Helgrindur | Pyroclastic cone(s) | 986 m (3,235 ft) | Unknown | 109 km |
| Vestmannaeyjar | Submarine | 283 m (928 ft) | 1973 | 109 km |
| Eyjafjallajokull | Stratovolcano | 1,651 m (5,417 ft) | 2010 | 117 km |
| Langjokull | Subglacial | 1,100 m (3,609 ft) | 950 | 122 km |
| Torfajokull | Stratovolcano | 1,280 m (4,199 ft) | 1477 | 129 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 30°F (-1°C) | 4.0 in | Coldest |
| February | 30°F (-1°C) | 4.3 in | Wettest |
| March | 30°F (-1°C) | 4.3 in | |
| April | 34°F (1°C) | 2.9 in | |
| May | 41°F (5°C) | 2.7 in | |
| June | 45°F (7°C) | 2.4 in | Driest |
| July | 49°F (9°C) | 2.6 in | Warmest |
| August | 48°F (9°C) | 3.5 in | |
| September | 43°F (6°C) | 3.4 in | |
| October | 37°F (3°C) | 4.1 in | |
| November | 32°F (0°C) | 3.9 in | |
| December | 30°F (-1°C) | 4.1 in |
Mosfellsbær has a seasonal temperature swing of 19°F / from 30°F in January to 49°F in July. Total annual precipitation is 42.2 inches, with February being the wettest month (4.3") and June the driest (2.4").