Altsasu weather in May

In May, Altsasu sees average daytime highs of 18°C and overnight lows near 9°C, with 106 mm of rain across 15.3 wet days and about 14.4 hours of daylight. It is the 5th-warmest and 4th-wettest month of the year here.

Highs climb over the month, from about 16°C in the first days to 19°C by the end. The sky is clear or mostly clear about 18% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 54 min at the start of May to 14 h 54 min by month's end. Set against the rest of the year, May is Altsasu's 7th-clearest and 8th-windiest month. For the whole year in context, see Altsasu's year-round climate.

Daytime high
18°
5th warmest
Overnight low
7th coldest
Rainfall
106 mm
15.3 wet days
Daylight
14 h 24 min
5:51 AM – 8:18 PM
Cloud cover
68%
7th clearest
Wind
8 km/h
8th windiest
Solar energy
5.47 kWh/m²
Travel score
5.0
out of 10

Altsasu is municipality of Spain.

Density
276/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 16°C in the first days to 19°C by the end.

A typical May day in Altsasu reaches about 18°C in the afternoon and slips back to 9°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 24°C. Set against its neighbours, May runs about 3°C warmer than April and about 3°C cooler than June.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1168
2168
3178
4178
5178
6178
7178
8178
9178
10178
11178
12179
13179
14189
15189
16189
17189
18189
19189
20189
21189
22189
231910
241910
251910
261910
271910
281910
291910
301910
312011

How May really feels in Altsasu

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Altsasu weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 11315.13.39.21.5
Feb10° / 10313.6410.22.0
Mar13° / 100142.211.63.2
Apr15° / 113160.613.13.7
May18° / 10615.3014.45.0
Jun21° / 12°7911.6015.16.2
Jul23° / 14°5910.4014.86.9
Aug24° / 14°6511.8013.86.8
Sep21° / 12°7011.6012.36.2
Oct18° / 9612.70.110.85.3
Nov12° / 127150.89.52.8
Dec / 10113.82.28.91.8

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 18% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 67%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13070
23070
33070
43070
53070
63070
73070
83070
93070
103070
113070
123070
133070
143070
153070
163169
173268
183367
193367
203466
213565
223565
233565
243664
253664
263664
273763
283763
293862
303862
313862

Chance of precipitation in May

Any precipitation

Altsasu gets around 106 mm of rain over 15.3 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 50% and peaks near 56% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
156
256
356
455
555
655
754
854
953
1053
1152
1251
1351
1450
1550
1649
1748
1848
1947
2047
2146
2246
2345
2445
2545
2645
2745
2845
2945
3045
3145

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 91% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19910
29820
39820
49820
59820
69730
79730
89730
99640
109640
119640
129640
139550
149550
159550
169460
179460
189370
199280
209190
2190100
2289110
2387130
2485141
2583161
2682171
2780191
2878211
2976222
3075232
3173252

Wind in May

Winds average 8 km/h in May.

Across May, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 54 min at the start of May to 14 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 6:10 AM to 5:39 AM, and sunset from 8:01 PM to 8:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.96:108:01
213.96:098:03
313.96:078:04
414.06:068:05
514.06:058:06
614.16:038:07
714.16:028:08
814.16:018:10
914.26:008:11
1014.25:588:12
1114.35:578:13
1214.35:568:14
1314.35:558:15
1414.45:548:16
1514.45:538:17
1614.45:518:18
1714.55:508:19
1814.55:498:20
1914.65:488:22
2014.65:488:23
2114.65:478:24
2214.65:468:25
2314.75:458:26
2414.75:448:27
2514.75:438:27
2614.85:428:28
2714.85:428:29
2814.85:418:30
2914.85:408:31
3014.95:408:32
3114.95:398:33

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.47 kWh/m².

For context, solar energy here swings from a low near 1.42 kWh/m² to a high of 5.91 kWh/m² in June across the year — May's 5.47 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.1Bright
25.1Bright
35.1Bright
45.1Bright
55.2Bright
65.2Bright
75.2Bright
85.2Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.4Bright
145.4Bright
155.4Bright
165.4Bright
175.5Bright
185.5Bright
195.5Bright
205.5Bright
215.6Bright
225.6Bright
235.6Bright
245.6Bright
255.7Bright
265.7Bright
275.7Bright
285.7Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in May

Is May a good time to visit Altsasu?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.0
Sightseeing
6th-best month of the year
1.6
Beach & pool
6th-best month of the year

May is a reasonable time to visit Altsasu for sightseeing.

What to pack for Altsasu in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Altsasu sees daytime highs around 18°C and nights near 9°C. Pack rain gear. Worth having: sun protection. About 15 days see rain.

rain gearsun protection

Sea temperature near Altsasu in May

The nearest coast averages about 16°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 53 km away) is warmest in August at about 22°C and coldest in February near 12°C.

It's comfortable for a long swim from Jul 2 to Sep 25 — about 2.8 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb12Bracing
Mar13Bracing
Apr14Bracing
May16Cool
Jun19Cool
Jul21Refreshing
Aug22Refreshing
Sep21Refreshing
Oct18Cool
Nov16Cool
Dec14Bracing

UV index in Altsasu in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Altsasu peaks around July 15 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 15UV 9Dec 20UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar5Moderate
Apr6High
May7High
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Altsasu?

Altsasu sits at 42.9°N, 2.2°W, 0 m above sea level, in Spain. The nearest listed city is Tolosa, 27 km away.

Topography around Altsasu

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Altsasu.

Within 3 km, the terrain around Altsasu has large variations in elevation — a maximum elevation change of 625 m around an average of 594 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,365 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,532 m.

The land around Altsasu is covered by trees (66%) and grassland (24%) within 3 km, trees (72%) and grassland (23%) within 16 km, and trees (44%) and cropland (22%) within 80 km.

3 km
625 m
16 km
1,365 m
80 km
1,532 m
treesshrubsgrasslandcroplandartificial surfaceswater
May weather nearby: Tolosa 27 km · Arrasate / Mondragón 32 km · Eibar 40 km · Barañáin 41 km · Oria 41 km · Gasteiz / Vitoria 42 km · Ermitagaña 42 km · Ermua 42 km

Spain travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 65% of US
price level, 2025
GDP per capita
$38,627
2025
Happiness
6.5 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.7
per 100k, 2023
Road deaths
3.9
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 540
Religion
Roman Catholic 58%atheist 16%agnostic 11%non-believer 11%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Altsasu (42.9°, -2.1652°, elevation 0 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).