Turrialba weather in September

In September, Turrialba sees average daytime highs of 23°C and overnight lows near 16°C, with 354 mm of rain across 29.5 wet days and about 12.1 hours of daylight. It is the 1st-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 23°C through the month. The sky is clear or mostly clear about 0% of the time in September, and the air most often feels humid.

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 Turrialba's 7th-clearest and 11th-windiest month. For the whole year in context, see Turrialba's year-round climate.

Daytime high
23°
1st warmest
Overnight low
16°
9th coldest
Rainfall
354 mm
29.5 wet days
Daylight
12 h 06 min
5:27 AM – 5:31 PM
Cloud cover
91%
7th clearest
Wind
4 km/h
11th windiest
Solar energy
4.5 kWh/m²
Travel score
3.5
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 23°C through the month.

A typical September day in Turrialba reaches about 23°C in the afternoon and slips back to 16°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 25°C. Set against its neighbours, September runs on par with August and on par with October.

15°18°20°23°25°151015202530
Avg high (°C)Avg low (°C)
12316
22316
32316
42316
52316
62316
72316
82316
92316
102316
112316
122316
132316
142316
152316
162316
172316
182316
192316
202316
212316
222316
232316
242316
252317
262317
272317
282317
292317
302317

Turrialba weather by month

How September compares with the rest of the year at a glance. September is the 1st-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan20° / 14°22819.911.55.0
Feb21° / 14°15417.811.75.0
Mar21° / 14°15121.911.94.7
Apr22° / 15°16024.212.24.2
May23° / 17°38929.812.43.6
Jun23° / 17°34029.412.63.5
Jul23° / 17°27729.412.53.6
Aug23° / 16°28629.612.33.6
Sep23° / 16°35429.512.13.5
Oct23° / 16°46130.311.83.5
Nov22° / 16°42727.811.53.7
Dec21° / 15°30822.411.44.5

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 (%)
1397
2397
3397
4397
5397
6397
7397
8397
9397
10397
11397
12397
13397
14397
15397
16397
17496
18496
19496
20496
21496
22397
23397
24397
25397
26397
27397
28298
29298
30298

Chance of precipitation in September

Any precipitation

Turrialba gets around 354 mm of rain over 29.5 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 98% and peaks near 99% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
197
297
397
497
597
698
798
898
998
1098
1198
1298
1398
1498
1598
1698
1798
1898
1998
2098
2199
2299
2399
2499
2599
2699
2799
2899
2999
3099

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 89% of days. Sticky, muggy-or-worse air turns up on roughly 10% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)
11918
21918
31918
41918
51918
61927
71927
81927
91927
101927
111927
121918
131918
141918
151909
161909
1718910
1818910
1918811
2018811
2118712
2218712
2318712
2418613
2518613
2618613
2718613
2818613
2918613
3018613

Wind in September

Winds average 4 km/h in September.

Across September, daily wind ranges from about 4 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
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

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 5:26 AM, and sunset from 5:40 PM to 5:22 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:295:40
212.25:295:40
312.25:295:39
412.25:285:38
512.25:285:38
612.15:285:37
712.15:285:36
812.15:285:36
912.15:285:35
1012.15:285:35
1112.15:285:34
1212.15:285:33
1312.15:285:33
1412.15:285:32
1512.15:285:31
1612.15:275:31
1712.05:275:30
1812.05:275:29
1912.05:275:29
2012.05:275:28
2112.05:275:27
2212.05:275:27
2312.05:275:26
2412.05:275:25
2512.05:275:25
2612.05:275:24
2712.05:275:24
2811.95:265:23
2911.95:265:22
3011.95:265:22

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.5 kWh/m².

For context, solar energy here swings from a low near 3.59 kWh/m² to a high of 5.71 kWh/m² in March across the year — September's 4.5 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.6Bright
44.6Bright
54.6Bright
64.6Bright
74.6Bright
84.6Bright
94.6Bright
104.6Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.5Bright
174.5Bright
184.5Bright
194.5Bright
204.4Bright
214.4Bright
224.4Bright
234.4Bright
244.4Bright
254.4Bright
264.4Bright
274.3Bright
284.3Bright
294.3Bright
304.3Bright
Planning a trip in September

Is September a good time to visit Turrialba?

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

3.5
Sightseeing
10th-best month of the year
2.9
Beach & pool
4th-best month of the year

September is a weaker month for outdoor sightseeing in Turrialba.

What to pack for Turrialba in September

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

In September, Turrialba sees daytime highs around 23°C and nights near 16°C. Pack rain gear. Worth having: light clothes and sun protection. About 30 days see rain.

rain gearlight clothessun protection

Sea temperature near Turrialba 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 62 km away) is warmest in September at about 29°C and coldest in January near 27°C.

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

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar28Warm
Apr28Tropical
May29Tropical
Jun29Tropical
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov28Tropical
Dec28Warm

UV index in Turrialba 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 Turrialba peaks around March 20 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 10 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 20UV 14Dec 15UV 10
UV index (midday)Level
Jan12Extreme
Feb13Extreme
Mar14Extreme
Apr14Extreme
May13Extreme
Jun13Extreme
Jul12Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov11Extreme
Dec10Extreme

Air quality in Turrialba 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 Turrialba 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 Turrialba?

Turrialba sits at 9.9°N, 83.7°W, 674 m above sea level, in Costa Rica. The nearest listed city is Paraíso, 21 km away.

ParaísoCartagoSiquirresSan DiegoGuápilesIpísCurridabatPurral

Topography around Turrialba

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

Within 3 km, the terrain around Turrialba has large variations in elevation — a maximum elevation change of 654 m around an average of 757 m above sea level; within 16 km, extreme variations in elevation — a maximum elevation change of 3,066 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,765 m.

The land around Turrialba is covered by trees (67%) and grassland (21%) within 3 km, trees (76%) and grassland (22%) within 16 km, and trees (75%) within 80 km.

3 km
654 m
16 km
3,066 m
80 km
3,765 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Paraíso 21 km · Cartago 26 km · Siquirres 29 km · San Diego 35 km · Guápiles 37 km · Ipís 37 km · Curridabat 39 km · Purral 39 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 Turrialba (9.9037°, -83.6836°, elevation 674 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).