Guápiles weather in September

In September, Guápiles sees average daytime highs of 28°C and overnight lows near 21°C, with 270 mm of rain across 28.1 wet days and about 12.1 hours of daylight. It is the 1st-warmest and 7th-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 2% 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 Guápiles's 7th-clearest and 10th-windiest month. For the whole year in context, see Guápiles's year-round climate.

Daytime high
28°
1st warmest
Overnight low
21°
8th coldest
Rainfall
270 mm
28.1 wet days
Daylight
12 h 06 min
5:28 AM – 5:31 PM
Cloud cover
87%
7th clearest
Wind
4 km/h
10th windiest
Solar energy
4.67 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 28°C through the month.

A typical September day in Guápiles reaches about 28°C in the afternoon and slips back to 21°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 30°C. Set against its neighbours, September runs on par with August and on par with October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12821
22821
32821
42821
52821
62821
72821
82821
92821
102821
112821
122821
132821
142821
152821
162821
172821
182821
192821
202821
212821
222821
232821
242821
252821
262821
272821
282821
292821
302821

Guápiles weather by month

How September compares with the rest of the year at a glance. September is the 1st-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 19°26817.311.55.8
Feb26° / 19°16313.711.76.1
Mar27° / 19°13614.211.96.0
Apr28° / 20°11716.912.25.2
May28° / 21°33426.912.53.6
Jun28° / 21°30628.812.63.1
Jul28° / 21°28128.412.53.5
Aug28° / 21°24628.312.33.4
Sep28° / 21°27028.112.13.2
Oct28° / 21°36829.311.83.4
Nov27° / 20°42826.311.53.9
Dec26° / 20°35321.411.45.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 2% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 7% of September, with mostly cloudy or overcast conditions the remaining 92%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22892
23892
24892
25892
26793
27793
28793
29694
30694

Chance of precipitation in September

Any precipitation

Guápiles gets around 270 mm of rain over 28.1 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 94% and peaks near 96% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
190
290
391
491
591
691
792
892
992
1093
1193
1293
1393
1494
1594
1694
1794
1894
1995
2095
2195
2295
2395
2495
2595
2696
2796
2896
2996
3096

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 84% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)
12080
22080
31981
41981
51981
61882
71882
81882
91882
101783
111783
121783
131783
141783
151684
161684
171684
181585
191585
201486
211486
221486
231387
241387
251387
261288
271288
281288
291288
301288

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 5:27 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
612.25:295:38
712.15:295:37
812.15:285:36
912.15:285:36
1012.15:285:35
1112.15:285:34
1212.15:285:34
1312.15:285:33
1412.15:285:32
1512.15:285:32
1612.15:285:31
1712.05:285:30
1812.05:285:30
1912.05:285:29
2012.05:275:28
2112.05:275:28
2212.05:275:27
2312.05:275:27
2412.05:275:26
2512.05:275:25
2612.05:275:25
2711.95:275:24
2811.95:275:23
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 4.67 kWh/m².

For context, solar energy here swings from a low near 3.5 kWh/m² to a high of 5.54 kWh/m² in March across the year — September's 4.67 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.8Bright
54.8Bright
64.8Bright
74.7Bright
84.7Bright
94.7Bright
104.7Bright
114.7Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.7Bright
174.7Bright
184.6Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.5Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.4Bright
Planning a trip in September

Is September a good time to visit Guápiles?

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

3.2
Sightseeing
11th-best month of the year
3.8
Beach & pool
9th-best month of the year

September is a weaker month for outdoor sightseeing in Guápiles.

What to pack for Guápiles in September

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

In September, Guápiles sees daytime highs around 28°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 28 days see rain.

light clothesrain gearsun protection

Sea temperature near Guápiles 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 48 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 Guápiles 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 Guápiles peaks around March 20 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 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 13Dec 16UV 9
UV index (midday)Level
Jan11Extreme
Feb12Extreme
Mar14Extreme
Apr13Extreme
May12Extreme
Jun13Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec9Very high

Air quality in Guápiles 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 Guápiles is worst in July — around 23 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (January, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1423 µg/m³Jan 1210 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb11Good
Mar12Moderate
Apr22Moderate
May23Moderate
Jun22Moderate
Jul23Moderate
Aug20Moderate
Sep18Moderate
Oct16Moderate
Nov12Moderate
Dec10Good
Location & terrain

Where is Guápiles?

Guápiles sits at 10.2°N, 83.8°W, 254 m above sea level, in Costa Rica. The nearest listed city is Siquirres, 33 km away.

SiquirresTurrialbaIpísPurralSan Vicente de MoraviaSan VicenteCartagoSan Pablo

Topography around Guápiles

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

Within 3 km, the terrain around Guápiles has only modest variations in elevation — a maximum elevation change of 190 m around an average of 253 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,700 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,471 m.

The land around Guápiles is covered by trees (48%) and grassland (34%) within 3 km, trees (70%) and grassland (26%) within 16 km, and trees (70%) within 80 km.

3 km
190 m
16 km
1,700 m
80 km
3,471 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Siquirres 33 km · Turrialba 37 km · Ipís 38 km · Purral 40 km · San Vicente de Moravia 41 km · San Vicente 41 km · Cartago 42 km · San Pablo 42 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 Guápiles (10.2168°, -83.7848°, elevation 254 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).