San Juan del Sur weather in September

In September, San Juan del Sur sees average daytime highs of 28°C and overnight lows near 25°C, with 252 mm of rain across 27.2 wet days and about 12.1 hours of daylight. It is the 6th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 9% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is San Juan del Sur's 9th-clearest and 12th-windiest month. For the whole year in context, see San Juan del Sur's year-round climate.

Daytime high
28°
6th warmest
Overnight low
25°
8th coldest
Rainfall
252 mm
27.2 wet days
Daylight
12 h 06 min
5:36 AM – 5:40 PM
Cloud cover
77%
9th clearest
Wind
15 km/h
12th windiest
Solar energy
5.48 kWh/m²
Travel score
3.4
out of 10

San Juan del Sur is Town in Nicaragua, Seat of the San Juan del Sur Municipality, Rivas Department.

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical September day in San Juan del Sur reaches about 28°C in the afternoon and slips back to 25°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 29°C. Set against its neighbours, September runs on par with August and on par with October.

20°23°25°28°30°151015202530
Avg high (°C)Avg low (°C)
12825
22825
32825
42825
52825
62825
72825
82825
92825
102825
112825
122825
132825
142825
152825
162825
172825
182825
192825
202825
212825
222825
232825
242825
252825
262825
272825
282825
292825
302825

How September really feels in San Juan del Sur

Once humidity and wind are folded in, September averages 11 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
11
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

San Juan del Sur weather by month

How September compares with the rest of the year at a glance. September is the 6th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 24°103.411.48.0
Feb28° / 24°41.411.68.2
Mar29° / 24°30.911.97.4
Apr30° / 25°143.112.26.2
May29° / 26°15316.312.54.4
Jun28° / 25°19826.512.63.4
Jul28° / 25°15125.812.63.7
Aug28° / 25°16826.412.43.6
Sep28° / 25°25227.212.13.4
Oct28° / 25°29027.411.73.8
Nov28° / 25°10215.411.55.6
Dec27° / 24°246.311.47.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 9% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 78%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12476
22377
32377
42476
52476
62476
72476
82377
92377
102476
112377
122377
132377
142377
152179
162179
172179
182080
192080
202080
212080
222080
232080
242080
252080
262080
272080
282179
292179
302179

Chance of precipitation in September

Any precipitation

San Juan del Sur gets around 252 mm of rain over 27.2 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 90% and peaks near 94% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
187
287
387
487
587
687
787
887
987
1088
1188
1288
1389
1489
1589
1690
1791
1891
1992
2092
2193
2293
2393
2494
2594
2694
2794
2894
2994
3094

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 73% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
17723
27723
37624
47525
57426
67426
77327
87228
97228
107129
117129
127030
137030
147030
157030
167030
177030
187030
197030
207129
217129
227228
237228
247327
257327
267426
277426
287426
297525
307525

Wind in September

Winds average 15 km/h in September, the calmest month.

Across September, daily wind ranges from about 14 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over September. Sunrise moves from 5:37 AM to 5:35 AM, and sunset from 5:50 PM to 5:30 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:375:50
212.25:375:49
312.25:375:48
412.25:375:48
512.25:365:47
612.25:365:46
712.25:365:46
812.15:365:45
912.15:365:44
1012.15:365:44
1112.15:365:43
1212.15:365:42
1312.15:365:42
1412.15:365:41
1512.15:365:40
1612.15:365:40
1712.15:365:39
1812.05:365:38
1912.05:365:38
2012.05:365:37
2112.05:365:36
2212.05:365:36
2312.05:365:35
2412.05:365:34
2512.05:365:33
2612.05:365:33
2711.95:355:32
2811.95:355:31
2911.95:355:31
3011.95:355:30

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.48 kWh/m².

For context, solar energy here swings from a low near 4.95 kWh/m² to a high of 6.93 kWh/m² in April across the year — September's 5.48 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.7Bright
45.7Bright
55.7Bright
65.7Bright
75.6Bright
85.6Bright
95.6Bright
105.6Bright
115.6Bright
125.6Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.4Bright
195.4Bright
205.4Bright
215.4Bright
225.3Bright
235.3Bright
245.3Bright
255.3Bright
265.3Bright
275.2Bright
285.2Bright
295.2Bright
305.2Bright
Planning a trip in September

Hazard calendar for San Juan del Sur

In seasonPeak

In September, San Juan del Sur sits inside its atlantic hurricane and monsoon season. The full year is below, with each hazard's peak months called out.

San Juan del Sur sits in the Atlantic hurricane belt; the season peaks August–October.

San Juan del Sur's monsoon runs May–October, when most of the year's rain falls.

Atlantic hurricane
Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit San Juan del Sur?

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

3.4
Sightseeing
11th-best month of the year
4.0
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in San Juan del Sur.

What to pack for San Juan del Sur in September

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

In September, San Juan del Sur sees daytime highs around 28°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 27 days see rain.

light clothesrain gearsun protection

Sea temperature near San Juan del Sur in September

The nearest coast averages about 29°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 14 km away) is warmest in September at about 29°C and coldest in February near 26°C.

The water stays above 20°C all year — warm enough for a swim any month.

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan26Warm
Feb26Warm
Mar26Warm
Apr28Warm
May29Tropical
Jun29Tropical
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct28Tropical
Nov27Warm
Dec27Warm

UV index in San Juan del Sur in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Juan del Sur peaks around March 20 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 9 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highMar 20UV 14Dec 15UV 9
UV index (midday)Level
Jan11Extreme
Feb13Extreme
Mar14Extreme
Apr13Extreme
May12Extreme
Jun13Extreme
Jul12Extreme
Aug13Extreme
Sep12Extreme
Oct11Extreme
Nov10Very high
Dec9Very high

Air quality in San Juan del Sur in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in San Juan del Sur is worst in July — around 23 µg/m³ PM2.5 (moderate), about 3.8× the cleanest month (December, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1622 µg/m³Dec 166 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar9Good
Apr19Moderate
May21Moderate
Jun19Moderate
Jul23Moderate
Aug18Moderate
Sep13Moderate
Oct9Good
Nov6Good
Dec6Good
Location & terrain

Where is San Juan del Sur?

San Juan del Sur sits at 11.3°N, 85.9°W, 0 m above sea level, in Nicaragua. The nearest listed city is Rivas, 21 km away.

NandaimeJinotepeGranadaDiriambaMasatepeSan MarcosLiberia

Topography around San Juan del Sur

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

Within 3 km, the terrain around San Juan del Sur has only modest variations in elevation — a maximum elevation change of 234 m around an average of 39 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 430 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,874 m.

The land around San Juan del Sur is covered by trees (45%) and water (37%) within 3 km, water (46%) and trees (39%) within 16 km, and water (62%) and trees (29%) within 80 km.

3 km
234 m
16 km
430 m
80 km
1,874 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Rivas 21 km · Nandaime 59 km · Jinotepe 75 km · Granada 76 km · Diriamba 78 km · Masatepe 79 km · San Marcos 82 km · Liberia 83 km

Nicaragua travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 34% of US
price level, 2025
GDP per capita
$3,173
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
11.3
per 100k, 2021
Road deaths
16.9
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
Moderate
EF EPI 512
Religion
Roman Catholic 45%Protestant 39%none 14%other 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 Juan del Sur (11.2529°, -85.8705°, 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).