Ipís weather in September

In September, Ipís sees average daytime highs of 23°C and overnight lows near 16°C, with 391 mm of rain across 29.1 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 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 Ipís's 10th-clearest and 12th-windiest month. For the whole year in context, see Ipís's year-round climate.

Daytime high
23°
3rd warmest
Overnight low
16°
7th coldest
Rainfall
391 mm
29.1 wet days
Daylight
12 h 06 min
5:29 AM – 5:32 PM
Cloud cover
92%
10th clearest
Wind
4 km/h
12th windiest
Solar energy
4.36 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 Ipís 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 21°C and 24°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)
12316
22316
32316
42316
52316
62316
72316
82316
92316
102316
112316
122316
132316
142316
152316
162316
172316
182316
192316
202316
212316
222316
232316
242316
252316
262316
272316
282316
292316
302316

Ipís 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
Jan21° / 14°10413.311.56.0
Feb22° / 14°6811.911.76.2
Mar23° / 14°6513.911.96.1
Apr23° / 15°1021812.25.3
May23° / 16°35727.812.53.8
Jun23° / 16°38528.812.63.5
Jul23° / 16°29328.212.53.7
Aug23° / 16°34528.512.33.7
Sep23° / 16°39129.112.13.5
Oct22° / 16°43030.111.83.4
Nov22° / 15°31225.511.54.0
Dec21° / 15°17017.811.45.3

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 2% of September, with mostly cloudy or overcast conditions the remaining 97%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1298
2298
3298
4298
5298
6298
7298
8298
9298
10298
11298
12298
13298
14298
15298
16298
17298
18298
19298
20298
21298
22298
23298
24298
25298
26298
27298
28298
29298
30298

Chance of precipitation in September

Any precipitation

Ipís gets around 391 mm of rain over 29.1 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 97% and peaks near 98% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
194
295
395
495
596
696
796
897
997
1097
1197
1297
1397
1497
1597
1697
1797
1897
1997
2097
2198
2298
2398
2498
2598
2698
2798
2898
2998
3098

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 96% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)
15941
25941
35950
44960
54960
64960
74960
84951
94951
104951
114951
124951
134951
144951
154951
163961
173961
183961
193961
203961
213961
223961
233961
243961
253961
263961
273961
283961
293961
304951

Wind in September

Winds average 4 km/h in September, the calmest month.

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 5:30 AM to 5:28 AM, and sunset from 5:42 PM to 5:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:305:42
212.25:305:41
312.25:305:40
412.25:305:40
512.25:305:39
612.15:305:38
712.15:305:38
812.15:295:37
912.15:295:37
1012.15:295:36
1112.15:295:35
1212.15:295:35
1312.15:295:34
1412.15:295:33
1512.15:295:33
1612.15:295:32
1712.05:295:31
1812.05:295:31
1912.05:295:30
2012.05:285:29
2112.05:285:29
2212.05:285:28
2312.05:285:27
2412.05:285:27
2512.05:285:26
2612.05:285:26
2712.05:285:25
2811.95:285:24
2911.95:285:24
3011.95:285:23

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.36 kWh/m².

For context, solar energy here swings from a low near 3.58 kWh/m² to a high of 5.78 kWh/m² in March across the year — September's 4.36 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.4Bright
84.4Bright
94.4Bright
104.4Bright
114.4Bright
124.4Bright
134.4Bright
144.4Bright
154.3Bright
164.3Bright
174.3Bright
184.3Bright
194.3Bright
204.3Bright
214.3Bright
224.3Bright
234.3Bright
244.3Bright
254.2Bright
264.2Bright
274.2Bright
284.2Bright
294.2Bright
304.2Bright
Planning a trip in September

Is September a good time to visit Ipís?

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
2.7
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Ipís.

What to pack for Ipís in September

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

In September, Ipís sees daytime highs around 23°C and nights near 16°C. Pack rain gear. Worth having: light clothes. About 29 days see rain.

rain gearlight clothes

Sea temperature near Ipís 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 67 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 Ipís 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 Ipís 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 Ipís 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 Ipís 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 Ipís?

Ipís sits at 10.0°N, 84.0°W, 1,310 m above sea level, in Costa Rica. The nearest listed city is Purral, 2.0 km away.

Topography around Ipís

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

Within 3 km, the terrain around Ipís has significant variations in elevation — a maximum elevation change of 336 m around an average of 1,336 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,398 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,764 m.

The land around Ipís is covered by artificial surfaces (55%) and trees (36%) within 3 km, trees (58%) and artificial surfaces (25%) within 16 km, and trees (74%) within 80 km.

3 km
336 m
16 km
2,398 m
80 km
3,764 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Purral 2.0 km · San Vicente de Moravia 3.0 km · San Vicente 3.0 km · Guadalupe 5.0 km · San Pedro 5.0 km · Calle Blancos 6.0 km · Curridabat 6.0 km · San Juan 7.0 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 Ipís (9.9655°, -84.0182°, elevation 1,310 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).