Altsasu, Spain experiences average highs of 17°C (63°F) and lows of 9°C (48°F) throughout the year. Rainfall is frequent, averaging about 14 rainy days per month. Sunshine is abundant, averaging about 9 hours per day. Average highs have warmed by 0.8°C (1.4°F) across the available records.
Altsasu, Spain Weather & Climate 2026
Monthly climate averages for Altsasu, Spain. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Feb–Dec 
Wetter season: Jan–Nov At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
6/10
Best: June, July, August, September
UV Index
4
Low
Temperature 17°C / 9°C
Feels Like 16°C / 8°C
Rainy Days 14
Rainfall 102 mm
Sunshine 9 h
Humidity 82%
Wind Speed 14 km/h
Dew Point 10°C
Snow Days 3 days
Frost Days 3 days
Hottest Month
26°C
August
Avg Low16°C
Rain10days
Coldest Month
3°C
January
Avg High9°C
Rain15days
Driest Month
10days
July
Avg High25°C
Avg Low15°C
Windiest Month
16 km/h
March (Gusts 48)
Worst Time to Visit
Consider avoiding January, February, December due to frequent rain.
Sun Position
Sunrise 06:31
Daylight 15.3h
Sunset 21:50
Live conditions—
Altsasu on the map · live conditions
Altsasu, Spain
- Continent
- Europe
- Country
- Spain
- City
- Altsasu
- Population
- 7.4K
- Coordinates
- 42.90°, -2.17°
Seasonal Breakdown
Spring
Mar–May
Avg High 16°C
Avg Low 7°C
Rain 16 days/mo
Summer
Jun–Aug
Avg High 25°C
Avg Low 15°C
Rain 12 days/mo
3/3 best months
Autumn
Sep–Nov
Avg High 18°C
Avg Low 10°C
Rain 13 days/mo
1/3 best months
Winter
Dec–Feb
Avg High 10°C
Avg Low 3°C
Rain 14 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: 9°C / 3°C . Feb: 12°C / 4°C . Mar: 13°C / 5°C . Apr: 15°C / 7°C . May: 19°C / 10°C . Jun: 23°C / 14°C . Jul: 25°C / 15°C . Aug: 26°C / 16°C . Sep: 22°C / 14°C . Oct: 19°C / 11°C . Nov: 13°C / 6°C . Dec: 11°C / 4°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 130 mm. Feb: 101 mm. Mar: 111 mm. Apr: 104 mm. May: 104 mm. Jun: 112 mm. Jul: 50 mm. Aug: 59 mm. Sep: 90 mm. Oct: 114 mm. Nov: 136 mm. Dec: 113 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 88%. Feb: 84%. Mar: 81%. Apr: 79%. May: 80%. Jun: 81%. Jul: 80%. Aug: 77%. Sep: 79%. Oct: 81%. Nov: 87%. Dec: 89%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 14 km/h . Feb: 14 km/h . Mar: 16 km/h . Apr: 15 km/h . May: 13 km/h . Jun: 12 km/h . Jul: 13 km/h . Aug: 12 km/h . Sep: 13 km/h . Oct: 14 km/h . Nov: 15 km/h . Dec: 14 km/h .
Sunshine
Sunshine
Sunshine: Jan: 6h. Feb: 7h. Mar: 9h. Apr: 10h. May: 11h. Jun: 11h. Jul: 12h. Aug: 11h. Sep: 10h. Oct: 8h. Nov: 6h. Dec: 6h.
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 2. Feb: UV 3. Mar: UV 4. Apr: UV 5. May: UV 6. Jun: UV 7. Jul: UV 7. Aug: UV 7. Sep: UV 5. Oct: UV 4. Nov: UV 2. Dec: UV 2.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 5 days. Feb: 4 days. Mar: 3 days. Apr: 1 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 2 days. Dec: 2 days.
Climate Trends
Average highs have warmed by 0.8°C (1.4°F) 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 | Aug 2025 · 28°C | Aug · 26°C |
| Coldest month | Jan 2025 · 3°C | Jan · 3°C |
| Wettest month | Nov 2025 · 142 mm | Nov · 136 mm |
| Windiest month | Mar 2025 · 18 km/h | Mar · 16 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Poor April
Fair May
Good June best
Excellent July best
Excellent August best
Excellent September best
Excellent October
Good November
Poor December
Poor | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 9°C / 3°C | 6°C / -1°C | 15days (130 mm) Wet | 5.9h Fair | 88% Very Muggy | 2 Low | Poor | View Details |
| February | 12°C / 4°C | 9°C / 1°C | 12days (101 mm) Wet | 7.1h Good | 84% Humid | 2.9 Moderate | Poor | View Details |
| March | 13°C / 5°C | 10°C / 2°C | 17days (111 mm) Wet | 8.6h Good | 81% Humid | 3.9 Moderate | Poor | View Details |
| April | 15°C / 7°C | 14°C / 4°C | 15days (104 mm) Wet | 9.6h Good | 79% Humid | 5.4 High | Fair | View Details |
| May | 19°C / 10°C | 18°C / 9°C | 16days (104 mm) Wet | 10.7h Excellent | 80% Humid | 6.2 High | Good | View Details |
| June best | 23°C / 14°C | 24°C / 14°C | 15days (112 mm) Wet | 10.8h Excellent | 81% Humid | 6.6 High | Excellent | View Details |
| July best | 25°C / 15°C | 27°C / 16°C | 10days (50 mm) Wet | 11.5h Excellent | 80% Humid | 7 High | Excellent | View Details |
| August best | 26°C / 16°C | 28°C / 17°C | 10days (59 mm) Wet | 11.1h Excellent | 77% Humid | 6.5 High | Excellent | View Details |
| September best | 22°C / 14°C | 23°C / 14°C | 12days (90 mm) Wet | 9.7h Good | 79% Humid | 5.1 High | Excellent | View Details |
| October | 19°C / 11°C | 18°C / 10°C | 12days (114 mm) Wet | 7.8h Good | 81% Humid | 3.5 Moderate | Good | View Details |
| November | 13°C / 6°C | 11°C / 4°C | 16days (136 mm) Wet | 6.2h Fair | 87% Very Muggy | 2.2 Moderate | Poor | View Details |
| December | 11°C / 4°C | 8°C / 1°C | 14days (113 mm) Wet | 5.9h Fair | 89% Very Muggy | 1.6 Low | Poor | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Altsasu are June, July, August, September, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Altsasu, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Altsasu is August, with average daytime highs of 26°C (79°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Altsasu is January, with average overnight lows of 3°C (37°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Altsasu is November, averaging 136mm of precipitation across 16 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Altsasu runs through March, May, November, January, with the heaviest rainfall in March. Based on 10-year averages for Altsasu.
Altsasu receives approximately 105 sunshine hours per year. The sunniest month is July with around 12 hours. Based on climate data for Altsasu.
The least favorable months to visit Altsasu are January, February, December, primarily due to frequent rain. For the best conditions, consider June, July, August, September instead.
The annual average UV index in Altsasu is 4, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Altsasu is 82%, classified as humid. High humidity makes warm temperatures feel significantly hotter — lightweight, breathable clothing is recommended.
Yes, Altsasu receives snow. Months with snowfall average 3 snow days and 5 cm (2 in) of accumulation, with about 3 frost days during winter.
Average wind speeds in Altsasu are 14 km/h (9 mph). The windiest month is March with peak winds reaching 16 km/h (10 mph) (gusts up to 48 km/h / 30 mph).
Altsasu averages 2 clear-sky days per month with overall cloud cover around 68%. The clearest skies occur in October.
The annual average dew point in Altsasu is 10°C (50°F), which feels pleasant with low humidity. Outdoor activities are comfortable year-round from a humidity standpoint.
Altsasu has a Oceanic climate, classified as Cfb under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Altsasu ranges from 8°C (46°F) to 16°C (61°F) on average. The 'feels like' temperature closely matches the actual temperature throughout most of the year.
Yes, June is a great time to visit Altsasu. It earns a climate score of 8/10 with Excellent.
For June in Altsasu, pack Umbrella, Waterproof jacket, Waterproof shoes, Sunscreen (SPF 30+), Sunglasses. With average highs of 23°C (73°F) and 15 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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