San Isidro weather in May

In May, San Isidro sees average daytime highs of 17°C and overnight lows near 12°C, with 72 mm of rain across 6.8 wet days and about 10.2 hours of daylight. It is the 8th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 16°C by the end. The sky is clear or mostly clear about 36% of the time in May, and the air most often feels dry.

Daylight stretches from about 10 h 36 min at the start of May to 9 h 54 min by month's end. Set against the rest of the year, May is San Isidro's 11th-clearest and 10th-windiest month. For the whole year in context, see San Isidro's year-round climate.

Daytime high
17°
8th warmest
Overnight low
12°
5th coldest
Rainfall
72 mm
6.8 wet days
Daylight
10 h 12 min
7:44 AM – 5:57 PM
Cloud cover
56%
11th clearest
Wind
15 km/h
10th windiest
Solar energy
2.66 kWh/m²
Travel score
6.1
out of 10

San Isidro is city in Buenos Aires Province, Argentina.

Founded
1706

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

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

A typical May day in San Isidro reaches about 17°C in the afternoon and slips back to 12°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 21°C. Set against its neighbours, May runs about 4°C cooler than April and about 3°C warmer than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
11913
21913
31913
41913
51913
61913
71913
81913
91813
101813
111813
121812
131812
141812
151812
161812
171712
181712
191712
201712
211712
221711
231711
241611
251611
261611
271611
281611
291611
301610
311610

San Isidro weather by month

How May compares with the rest of the year at a glance. May is the 8th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 20°836.9147.2
Feb26° / 20°998.113.37.1
Mar25° / 18°967.612.37.5
Apr21° / 15°1028.111.27.0
May17° / 12°726.810.26.1
Jun15° / 747.79.74.6
Jul14° / 747.19.94.2
Aug15° / 716.610.75.2
Sep17° / 11°807.111.86.0
Oct20° / 14°1199.812.96.5
Nov23° / 16°958.213.87.3
Dec26° / 19°878.114.37.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 51%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35644
45545
55545
65545
75545
85446
95446
105446
115347
125248
135149
145149
155050
164951
174951
184852
194852
204753
214654
224555
234456
244456
254456
264456
274456
284456
294555
304456
314456

Chance of precipitation in May

Any precipitation

San Isidro gets around 72 mm of rain over 6.8 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 22% and peaks near 24% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
124
224
324
423
523
623
722
822
922
1022
1122
1222
1323
1423
1523
1623
1723
1823
1923
2023
2123
2223
2323
2422
2522
2622
2721
2821
2921
3021
3121

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 66% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
15526172
25625172
35625172
45724172
55924161
65924161
76024151
86024151
96223141
106223141
116323131
126423121
136423121
146423121
156523111
166523111
176523111
186623101
196722101
206821101
216821101
22702091
23711991
24721891
25741781
26751681
27761671
28781561
29791461
30801451
31811351

Wind in May

Winds average 15 km/h in May.

Across May, daily wind ranges from about 15 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze
3116light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 10 h 36 min at the start of May to 9 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 42 minutes over May. Sunrise moves from 7:32 AM to 7:55 AM, and sunset from 6:10 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.67:326:10
210.67:336:09
310.67:346:08
410.57:356:07
510.57:356:06
610.57:366:05
710.57:376:04
810.47:386:03
910.47:396:02
1010.47:396:01
1110.37:406:01
1210.37:416:00
1310.37:425:59
1410.37:435:58
1510.27:435:57
1610.27:445:57
1710.27:455:56
1810.27:465:55
1910.17:465:54
2010.17:475:54
2110.17:485:53
2210.17:495:52
2310.07:495:52
2410.07:505:51
2510.07:515:51
2610.07:525:50
2710.07:525:50
289.97:535:49
299.97:545:49
309.97:545:48
319.97:555:48

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 2.66 kWh/m².

For context, solar energy here swings from a low near 2.25 kWh/m² to a high of 7.45 kWh/m² in December across the year — May's 2.66 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.2Moderate
23.1Moderate
33.1Moderate
43.1Moderate
53.0Moderate
63.0Moderate
73.0Moderate
82.9Moderate
92.9Moderate
102.9Moderate
112.8Moderate
122.8Moderate
132.8Moderate
142.7Moderate
152.7Moderate
162.6Moderate
172.6Moderate
182.6Moderate
192.5Moderate
202.5Moderate
212.5Moderate
222.5Moderate
232.5Moderate
242.4Moderate
252.4Moderate
262.4Moderate
272.4Moderate
282.4Moderate
292.4Moderate
302.3Moderate
312.3Moderate
Planning a trip in May

Is May a good time to visit San Isidro?

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

6.1
Sightseeing
8th-best month of the year
1.7
Beach & pool
8th-best month of the year

May is a reasonable time to visit San Isidro for sightseeing.

What to pack for San Isidro in May

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

In May, San Isidro sees daytime highs around 17°C and nights near 12°C. Little to plan around — just the basics. About 7 days see rain.

Sea temperature near San Isidro in May

The nearest coast averages about 17°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 17 km away) is warmest in January at about 25°C and coldest in July near 13°C.

It's comfortable for a long swim from Nov 9 to Apr 21 — about 5.4 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swimcomfortable to swim
Sea temperature (°C)Comfort
Jan25Warm
Feb25Warm
Mar24Refreshing
Apr21Refreshing
May17Cool
Jun14Bracing
Jul13Bracing
Aug14Bracing
Sep15Cool
Oct18Cool
Nov21Refreshing
Dec23Refreshing

UV index in San Isidro in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Isidro peaks around January 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 19 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateHighVery highExtremeJan 15UV 13Jun 19UV 3
UV index (midday)Level
Jan13Extreme
Feb11Extreme
Mar10Very high
Apr6High
May4Moderate
Jun3Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct8Very high
Nov11Extreme
Dec12Extreme

Air quality in San Isidro in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in San Isidro is worst in June — around 25 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (December, 12 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJun 2325 µg/m³Dec 1612 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb14Moderate
Mar16Moderate
Apr17Moderate
May22Moderate
Jun25Moderate
Jul25Moderate
Aug24Moderate
Sep19Moderate
Oct16Moderate
Nov13Moderate
Dec12Moderate
Location & terrain

Where is San Isidro?

San Isidro sits at 34.5°S, 58.5°W, 16 m above sea level, in Argentina. The nearest listed city is Tigre, 7.0 km away.

Topography around San Isidro

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

Within 3 km, the terrain around San Isidro has only modest variations in elevation — a maximum elevation change of 36 m around an average of 15 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 57 m; within 80 km, only modest variations in elevation — a maximum elevation change of 138 m.

The land around San Isidro is covered by artificial surfaces (50%) and trees (27%) within 3 km, artificial surfaces (33%) and water (31%) within 16 km, and grassland (24%), cropland (23%) and water (21%) within 80 km.

3 km
36 m
16 km
57 m
80 km
138 m
treesgrasslandcroplandartificial surfaceswaterwetland
May weather nearby: Tigre 7.0 km · Don Torcuato 10 km · General Pacheco 11 km · Belgrano 12 km · Villa Ortúzar 13 km · Colegiales 13 km · Santos Lugares 15 km · Villa de Mayo 15 km

Argentina travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / I
220 V · 50 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$14,898
2025
Happiness
6.4 / 10
World Happiness, 2025
Homicide rate
4.5
per 100k, 2023
Road deaths
14.1
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
High
EF EPI 575
Religion
Roman Catholic 63%none 19%Evangelical 15%Jehovah's Witness and Church of Jesus Christ 1%

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 San Isidro (-34.4697°, -58.5211°, elevation 16 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. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).