Paraíso weather in September

In September, Paraíso sees average daytime highs of 21°C and overnight lows near 14°C, with 343 mm of rain across 27.3 wet days and about 12.1 hours of daylight. It is the 3rd-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 21°C through the month. The sky is clear or mostly clear about 0% of the time in September, and the air most often feels comfortable.

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 Paraíso's 11th-clearest and 12th-windiest month. For the whole year in context, see Paraíso's year-round climate.

Daytime high
21°
3rd warmest
Overnight low
14°
8th coldest
Rainfall
343 mm
27.3 wet days
Daylight
12 h 06 min
5:28 AM – 5:31 PM
Cloud cover
93%
11th clearest
Wind
3 km/h
12th windiest
Solar energy
4.3 kWh/m²
Travel score
3.6
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 21°C through the month.

A typical September day in Paraíso reaches about 21°C in the afternoon and slips back to 14°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 23°C. Set against its neighbours, September runs on par with August and on par with October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
12114
22114
32114
42114
52114
62114
72114
82114
92114
102114
112114
122114
132114
142114
152114
162114
172114
182114
192114
202114
212114
222114
232114
242114
252114
262114
272114
282114
292114
302114

Paraíso weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan20° / 12°628.911.56.5
Feb20° / 12°457.111.76.8
Mar21° / 12°438.911.96.7
Apr22° / 13°6711.812.26.0
May22° / 14°33124.912.44.0
Jun21° / 15°29626.812.63.7
Jul21° / 14°21526.212.53.8
Aug21° / 14°25426.812.33.7
Sep21° / 14°34327.312.13.6
Oct21° / 14°42528.611.83.5
Nov20° / 14°27422.811.54.2
Dec20° / 13°11714.111.45.6

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 3% of September, with mostly cloudy or overcast conditions the remaining 97%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1298
2298
3298
4298
5298
6397
7397
8397
9397
10397
11397
12397
13397
14397
15397
16397
17397
18397
19397
20397
21397
22397
23397
24397
25397
26397
27298
28298
29298
30298

Chance of precipitation in September

Any precipitation

Paraíso gets around 343 mm of rain over 27.3 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 91% and peaks near 93% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
189
289
390
490
590
691
791
891
992
1092
1192
1292
1392
1492
1592
1692
1792
1892
1991
2091
2191
2291
2391
2492
2592
2692
2792
2893
2993
3093

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the comfortable band about 60% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
116633
216633
316633
416633
516633
616633
716534
806634
906535
1006436
1106436
1206337
1306238
1406139
1506040
1605941
1705842
1805842
1905743
2005743
2105743
2205743
2305644
2405644
2505644
2605644
2705743
2805743
2915643
3015643

Wind in September

Winds average 3 km/h in September, the calmest month.

Across September, daily wind ranges from about 3 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
83calm
93calm
103calm
113calm
123calm
133calm
143calm
153calm
163calm
173calm
183calm
193calm
203calm
213calm
223calm
233calm
243calm
253calm
263calm
273calm
283calm
293calm
303calm

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 5:29 AM to 5:27 AM, and sunset from 5:41 PM to 5:22 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:295:41
212.25:295:40
312.25:295:40
412.25:295:39
512.25:295:38
612.15:295:38
712.15:295:37
812.15:295:37
912.15:295:36
1012.15:295:35
1112.15:295:35
1212.15:295:34
1312.15:285:33
1412.15:285:33
1512.15:285:32
1612.15:285:31
1712.05:285:31
1812.05:285:30
1912.05:285:29
2012.05:285:29
2112.05:285:28
2212.05:285:28
2312.05:285:27
2412.05:275:26
2512.05:275:26
2612.05:275:25
2712.05:275:24
2811.95:275:24
2911.95:275:23
3011.95:275:22

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.3 kWh/m².

For context, solar energy here swings from a low near 3.75 kWh/m² to a high of 5.97 kWh/m² in March across the year — September's 4.3 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.4Bright
34.4Bright
44.4Bright
54.4Bright
64.4Bright
74.4Bright
84.4Bright
94.4Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.3Bright
174.3Bright
184.3Bright
194.2Bright
204.2Bright
214.2Bright
224.2Bright
234.2Bright
244.2Bright
254.2Bright
264.2Bright
274.2Bright
284.2Bright
294.1Bright
304.1Bright
Planning a trip in September

Hazard calendar for Paraíso

In seasonPeak

In September, Paraíso sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Paraíso's rainy season runs May–November, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Paraíso?

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

3.6
Sightseeing
11th-best month of the year
2.3
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Paraíso.

What to pack for Paraíso in September

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

In September, Paraíso sees daytime highs around 21°C and nights near 14°C. Pack rain gear. About 27 days see rain.

rain gear

Sea temperature near Paraíso 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 59 km away) 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 Paraíso 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 Paraíso peaks around March 19 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 19UV 15Dec 16UV 10
UV index (midday)Level
Jan12Extreme
Feb14Extreme
Mar15Extreme
Apr14Extreme
May13Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov12Extreme
Dec10Extreme

Air quality in Paraíso 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 Paraíso 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 Paraíso?

Paraíso sits at 9.8°N, 83.9°W, 1,306 m above sea level, in Costa Rica. The nearest listed city is Cartago, 6.0 km away.

TurrialbaSan MiguelIpísPurral

Topography around Paraíso

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

Within 3 km, the terrain around Paraíso has large variations in elevation — a maximum elevation change of 602 m around an average of 1,311 m above sea level; within 16 km, extreme variations in elevation — a maximum elevation change of 2,753 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,764 m.

The land around Paraíso is covered by trees (49%) and grassland (35%) within 3 km, trees (70%) and grassland (21%) within 16 km, and trees (75%) within 80 km.

3 km
602 m
16 km
2,753 m
80 km
3,764 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Cartago 6.0 km · San Diego 16 km · Patarrá 19 km · Curridabat 20 km · Turrialba 21 km · San Miguel 22 km · Ipís 22 km · Purral 22 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 Paraíso (9.8385°, -83.8666°, elevation 1,306 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).