Manuel Antonio weather in September

In September, Manuel Antonio sees average daytime highs of 27°C and overnight lows near 23°C, with 805 mm of rain across 29.9 wet days and about 12.1 hours of daylight. It is the 6th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 0% 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 Manuel Antonio's 8th-clearest and 2nd-windiest month. For the whole year in context, see Manuel Antonio's year-round climate.

Daytime high
27°
6th warmest
Overnight low
23°
5th coldest
Rainfall
805 mm
29.9 wet days
Daylight
12 h 06 min
5:29 AM – 5:32 PM
Cloud cover
94%
8th clearest
Wind
5 km/h
2nd windiest
Solar energy
4.18 kWh/m²
Travel score
3.2
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical September day in Manuel Antonio reaches about 27°C in the afternoon and slips back to 23°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 28°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)
12723
22723
32723
42723
52723
62723
72723
82723
92723
102723
112723
122723
132723
142723
152723
162723
172723
182723
192723
202723
212723
222723
232723
242723
252723
262723
272723
282723
292723
302723

Manuel Antonio weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 23°21626.411.54.3
Feb27° / 23°12521.111.74.8
Mar28° / 24°13124.511.94.5
Apr27° / 24°34228.312.23.6
May27° / 24°80530.912.43.2
Jun27° / 24°81929.912.53.2
Jul27° / 23°9063112.53.2
Aug27° / 23°9583112.33.2
Sep27° / 23°80529.912.13.2
Oct26° / 23°96330.911.83.2
Nov26° / 23°8983011.63.3
Dec27° / 23°49129.711.53.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 0% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 0% of September, with mostly cloudy or overcast conditions the remaining 100%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
10100
20100
30100
40100
50100
60100
70100
80100
90100
100100
110100
120100
130100
140100
150100
160100
170100
180100
190100
200100
210100
22199
23199
24199
25199
26199
27199
28199
29199
30199

Chance of precipitation in September

Any precipitation

Manuel Antonio gets around 805 mm of rain over 29.9 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 100% and peaks near 100% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
2399
2499
2599
2699
2799
2899
2999
3099

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 99% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
161000
171000
181000
191000
201000
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991

Wind in September

Winds average 5 km/h in September.

Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

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 5:31 AM to 5:28 AM, and sunset from 5:42 PM to 5:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:315:42
212.25:315:41
312.25:315:41
412.25:315:40
512.15:315:39
612.15:305:39
712.15:305:38
812.15:305:38
912.15:305:37
1012.15:305:36
1112.15:305:36
1212.15:305:35
1312.15:305:34
1412.15:305:34
1512.15:305:33
1612.15:295:32
1712.05:295:32
1812.05:295:31
1912.05:295:31
2012.05:295:30
2112.05:295:29
2212.05:295:29
2312.05:295:28
2412.05:295:27
2512.05:295:27
2612.05:285:26
2712.05:285:26
2811.95:285:25
2911.95:285:24
3011.95:285:24

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.18 kWh/m².

For context, solar energy here swings from a low near 3.79 kWh/m² to a high of 6.26 kWh/m² in March across the year — September's 4.18 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.2Bright
44.2Bright
54.2Bright
64.2Bright
74.2Bright
84.2Bright
94.2Bright
104.2Bright
114.2Bright
124.2Bright
134.2Bright
144.2Bright
154.2Bright
164.2Bright
174.2Bright
184.2Bright
194.2Bright
204.2Bright
214.2Bright
224.2Bright
234.2Bright
244.2Bright
254.2Bright
264.2Bright
274.1Bright
284.1Bright
294.1Bright
304.1Bright
Planning a trip in September

Is September a good time to visit Manuel Antonio?

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

3.2
Sightseeing
7th-best month of the year
3.3
Beach & pool
8th-best month of the year

September is a weaker month for outdoor sightseeing in Manuel Antonio.

What to pack for Manuel Antonio in September

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

In September, Manuel Antonio sees daytime highs around 27°C and nights near 23°C. Pack rain gear. Worth having: light clothes. About 30 days see rain.

rain gearlight clothes

Sea temperature near Manuel Antonio 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 offshore is warmest in March at about 30°C and coldest in November near 28°C.

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

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar30Tropical
Apr30Tropical
May29Tropical
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct28Tropical
Nov28Warm
Dec28Tropical

UV index in Manuel Antonio in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Manuel Antonio peaks around March 16 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 10 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 16UV 15Dec 16UV 10
UV index (midday)Level
Jan12Extreme
Feb14Extreme
Mar15Extreme
Apr14Extreme
May14Extreme
Jun14Extreme
Jul13Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov12Extreme
Dec10Extreme

Air quality in Manuel Antonio 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 Manuel Antonio is worst in May — around 19 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (January, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 1718 µg/m³Jan 149 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar11Good
Apr17Moderate
May19Moderate
Jun17Moderate
Jul18Moderate
Aug17Moderate
Sep16Moderate
Oct14Moderate
Nov12Good
Dec10Good
Location & terrain

Where is Manuel Antonio?

Manuel Antonio sits at 9.4°N, 84.2°W, 0 m above sea level, in Costa Rica. The nearest listed city is Tejar, 38 km away.

TejarSan Rafael AbajoSan IsidroAserríSan MiguelSan Rafael ArribaSan Juan de DiosPatarrá

Topography around Manuel Antonio

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

Within 3 km, the terrain around Manuel Antonio has only modest variations in elevation — a maximum elevation change of 195 m around an average of 40 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 821 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,764 m.

The land around Manuel Antonio is covered by trees (58%) and water (36%) within 3 km, water (52%) and trees (39%) within 16 km, and trees (52%) and water (36%) within 80 km.

3 km
195 m
16 km
821 m
80 km
3,764 m
treesgrasslandcroplandartificial surfaceswatermangroves
September weather nearby: Tejar 38 km · San Rafael Abajo 49 km · San Isidro 51 km · Aserrí 51 km · San Miguel 52 km · San Rafael Arriba 53 km · San Juan de Dios 53 km · Patarrá 54 km

Costa Rica travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 59% of US
price level, 2025
GDP per capita
$19,970
2025
Happiness
7.4 / 10
World Happiness, 2025
Safe drinking water
81%
of population, 2024
Homicide rate
17.7
per 100k, 2023
Road deaths
14.8
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 516
Religion
Roman Catholic 48%none 27%Evangelical and Pentecostal 20%other 3%

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 Manuel Antonio (9.4087°, -84.1558°, 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. 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).