Mosfellsbær, Iceland experiences average highs of 7°C (45°F) and lows of 1°C (34°F) throughout the year. Rainfall is frequent, averaging about 16 rainy days per month. Average highs have stayed broadly stable across the available records.
Mosfellsbær, Iceland Weather & Climate 2026
Monthly climate averages for Mosfellsbær, Iceland. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Apr–Dec 
Wetter season: Jan–Oct At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
2.6/10
Best: July
UV Index
2
Low
Temperature 7°C / 1°C
Feels Like 3°C / -2°C
Rainy Days 16
Rainfall 105 mm
Sunshine 6 h
Humidity 83%
Wind Speed 18 km/h
Dew Point 1°C
Snow Days 10 days
Frost Days 16 days
Hottest Month
15°C
July
Avg Low9°C
Rain13days
Coldest Month
-6°C
January
Avg High-1°C
Rain17days
Driest Month
13days
July
Avg High15°C
Avg Low9°C
Windiest Month
21 km/h
February (Gusts 53)
Sea Temperature
1°C – 13°C
Warmest water: August (
12.8°C
)
Worst Time to Visit
Consider avoiding January, February, March, April due to very cold temperatures, heavy rainfall.
Sun Position
Sunrise 02:57
Daylight 21h
Sunset 00:00
Live conditions—
Mosfellsbær on the map · live conditions
Mosfellsbær, Iceland
- Continent
- Europe
- Country
- Iceland
- City
- Mosfellsbær
- Population
- 12.1K
- Coordinates
- 64.17°, -21.70°
Seasonal Breakdown
Spring
Mar–May
Avg High 6°C
Avg Low 0°C
Rain 17 days/mo
Summer
Jun–Aug
Avg High 14°C
Avg Low 8°C
Rain 14 days/mo
1/3 best months
Autumn
Sep–Nov
Avg High 6°C
Avg Low 2°C
Rain 16 days/mo
Winter
Dec–Feb
Avg High 0°C
Avg Low -5°C
Rain 17 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: -1°C / -6°C . Feb: 1°C / -5°C . Mar: 3°C / -3°C . Apr: 6°C / 0°C . May: 10°C / 4°C . Jun: 13°C / 7°C . Jul: 15°C / 9°C . Aug: 14°C / 8°C . Sep: 11°C / 5°C . Oct: 6°C / 2°C . Nov: 2°C / -2°C . Dec: 0°C / -5°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 127 mm. Feb: 129 mm. Mar: 116 mm. Apr: 94 mm. May: 109 mm. Jun: 84 mm. Jul: 70 mm. Aug: 81 mm. Sep: 127 mm. Oct: 116 mm. Nov: 95 mm. Dec: 108 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 84%. Feb: 85%. Mar: 81%. Apr: 80%. May: 78%. Jun: 78%. Jul: 81%. Aug: 82%. Sep: 85%. Oct: 87%. Nov: 87%. Dec: 85%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 20 km/h . Feb: 21 km/h . Mar: 19 km/h . Apr: 19 km/h . May: 18 km/h . Jun: 17 km/h . Jul: 16 km/h . Aug: 16 km/h . Sep: 18 km/h . Oct: 18 km/h . Nov: 18 km/h . Dec: 18 km/h .
Sunshine
Sunshine
Sunshine: Jan: 1h. Feb: 3h. Mar: 6h. Apr: 9h. May: 11h. Jun: 10h. Jul: 10h. Aug: 9h. Sep: 7h. Oct: 4h. Nov: 2h. Dec: 1h.
Sea Temperature
Sea Temperatureswim
Line chart showing monthly sea temperature. Jan: 1°C . Feb: 2°C . Mar: 3°C . Apr: 5°C . May: 8°C . Jun: 10°C . Jul: 12°C . Aug: 13°C . Sep: 11°C . Oct: 8°C . Nov: 6°C . Dec: 3°C .
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 0. Feb: UV 1. Mar: UV 2. Apr: UV 3. May: UV 4. Jun: UV 4. Jul: UV 4. Aug: UV 3. Sep: UV 2. Oct: UV 1. Nov: UV 0. Dec: UV 0.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 18 days. Feb: 17 days. Mar: 15 days. Apr: 8 days. May: 3 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 1 days. Oct: 5 days. Nov: 9 days. Dec: 14 days.
Climate Trends
Average highs have stayed broadly stable across the available records. Average rainfall has remained broadly steady.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 15°C | Jul · 15°C |
| Coldest month | Jan 2025 · -8°C | Jan · -6°C |
| Wettest month | Mar 2025 · 172 mm | Feb · 129 mm |
| Windiest month | Feb 2025 · 24 km/h | Feb · 21 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Poor April
Poor May
Wet June
Fair July best
Good August
Fair September
Wet October
Poor November
Poor December
Poor | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | -1°C / -6°C | -5°C / -11°C | 17days (127 mm) Wet | 1.3h Poor | 84% Humid | 0.2 Low | Poor | View Details |
| February | 1°C / -5°C | -4°C / -9°C | 17days (129 mm) Wet | 3.3h Poor | 85% Humid | 0.8 Low | Poor | View Details |
| March | 3°C / -3°C | -2°C / -7°C | 17days (116 mm) Wet | 6.3h Fair | 81% Humid | 1.9 Low | Poor | View Details |
| April | 6°C / 0°C | 3°C / -4°C | 15days (94 mm) Wet | 8.6h Good | 80% Humid | 3.2 Moderate | Poor | View Details |
| May | 10°C / 4°C | 7°C / 1°C | 18days (109 mm) Wet | 10.6h Excellent | 78% Humid | 3.9 Moderate | Wet | View Details |
| June | 13°C / 7°C | 10°C / 4°C | 14days (84 mm) Wet | 10.1h Excellent | 78% Humid | 4 Moderate | Fair | View Details |
| July best | 15°C / 9°C | 13°C / 7°C | 13days (70 mm) Wet | 9.7h Good | 81% Humid | 3.8 Moderate | Good | View Details |
| August | 14°C / 8°C | 12°C / 6°C | 14days (81 mm) Wet | 8.9h Good | 82% Humid | 3.2 Moderate | Fair | View Details |
| September | 11°C / 5°C | 8°C / 2°C | 18days (127 mm) Wet | 6.8h Fair | 85% Humid | 2.2 Moderate | Wet | View Details |
| October | 6°C / 2°C | 3°C / -2°C | 17days (116 mm) Wet | 4.3h Fair | 87% Very Muggy | 1 Low | Poor | View Details |
| November | 2°C / -2°C | -1°C / -6°C | 13days (95 mm) Wet | 1.8h Poor | 87% Very Muggy | 0.4 Low | Poor | View Details |
| December | 0°C / -5°C | -4°C / -9°C | 16days (108 mm) Wet | 0.9h Poor | 85% Humid | 0.1 Low | Poor | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Mosfellsbær are July, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Mosfellsbær, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Mosfellsbær is July, with average daytime highs of 15°C (59°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Mosfellsbær is January, with average overnight lows of -6°C (21°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Mosfellsbær is February, averaging 129mm of precipitation across 17 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Mosfellsbær runs through May, September, January, February, with the heaviest rainfall in May. Based on 10-year averages for Mosfellsbær.
Mosfellsbær receives approximately 73 sunshine hours per year. The sunniest month is May with around 11 hours. Based on climate data for Mosfellsbær.
The least favorable months to visit Mosfellsbær are January, February, March, April, primarily due to very cold temperatures, heavy rainfall. For the best conditions, consider July instead.
The annual average UV index in Mosfellsbær is 2, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Mosfellsbær is 83%, classified as humid. High humidity makes warm temperatures feel significantly hotter — lightweight, breathable clothing is recommended.
Sea temperatures in Summer average 7°C (45°F), which most swimmers will find too cold without a wetsuit.
Yes, Mosfellsbær receives snow. Months with snowfall average 10 snow days and 21 cm (8 in) of accumulation, with about 16 frost days during winter.
Average wind speeds in Mosfellsbær are 18 km/h (11 mph). The windiest month is February with peak winds reaching 21 km/h (13 mph) (gusts up to 53 km/h / 33 mph).
Mosfellsbær averages 1 clear-sky days per month with overall cloud cover around 78%. The clearest skies occur in March.
The annual average dew point in Mosfellsbær is 1°C (34°F), which feels dry and comfortable. Outdoor activities are comfortable year-round from a humidity standpoint.
Mosfellsbær has a Subarctic climate, classified as Dfc under the Köppen system. Continental climates experience extreme temperature ranges — hot summers and cold, snowy winters.
The 'feels like' temperature in Mosfellsbær ranges from -2°C (28°F) to 3°C (37°F) on average. Wind chill makes winters feel noticeably colder than the actual temperature — layered clothing is recommended.
June is not the best time to visit Mosfellsbær, with a climate score of 5.3/10. Consider visiting during July instead for better conditions.
For June in Mosfellsbær, pack Layered clothing, Light jacket, Umbrella, Waterproof jacket, Waterproof shoes. With average highs of 13°C (55°F) and 14 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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