Liberia weather in September

In September, Liberia sees average daytime highs of 29°C and overnight lows near 22°C, with 352 mm of rain across 25.7 wet days and about 12.1 hours of daylight. It is the 8th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°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 Liberia's 11th-clearest and 12th-windiest month. For the whole year in context, see Liberia's year-round climate.

Daytime high
29°
8th warmest
Overnight low
22°
6th coldest
Rainfall
352 mm
25.7 wet days
Daylight
12 h 06 min
5:34 AM – 5:38 PM
Cloud cover
86%
11th clearest
Wind
5 km/h
12th windiest
Solar energy
4.96 kWh/m²
Travel score
3.1
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical September day in Liberia reaches about 29°C in the afternoon and slips back to 22°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 31°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13022
23022
33022
43022
53022
63022
73022
83022
93022
103022
113022
123022
133022
143022
153022
162922
172922
182922
192922
202922
212922
222922
232922
242922
252922
262922
272922
282922
292922
302922

How September really feels in Liberia

Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Liberia weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 22°30.611.47.1
Feb30° / 22°20.311.66.5
Mar32° / 22°30.911.95.4
Apr33° / 23°304.712.24.0
May32° / 23°24317.912.53.3
Jun30° / 23°27622.512.63.3
Jul30° / 23°16116.412.64.1
Aug30° / 22°20719.612.43.7
Sep29° / 22°35225.712.13.1
Oct29° / 22°36125.111.83.5
Nov29° / 22°10911.411.55.3
Dec29° / 22°12211.46.9

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 6% 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
8892
9892
10892
11892
12892
13793
14793
15793
16793
17793
18793
19793
20793
21793
22793
23793
24793
25793
26793
27793
28793
29793
30793

Chance of precipitation in September

Any precipitation

Liberia gets around 352 mm of rain over 25.7 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 85% and peaks near 91% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
178
278
379
479
580
680
780
881
981
1082
1182
1283
1384
1484
1585
1686
1787
1888
1989
2089
2190
2290
2391
2491
2591
2691
2790
2890
2990
3089

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 98% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
13961
22971
32971
42971
52971
62971
72971
82971
92971
101981
111981
121981
131981
141981
151981
161990
171990
181990
191990
201990
211990
221990
231990
241990
251990
261990
271990
281990
291990
301990

Wind in September

Winds average 5 km/h in September, the calmest month.

Across September, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
296calm
306calm

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 5:35 AM to 5:34 AM, and sunset from 5:48 PM to 5:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:355:48
212.25:355:47
312.25:355:46
412.25:355:46
512.25:355:45
612.25:355:44
712.15:355:44
812.15:355:43
912.15:355:43
1012.15:355:42
1112.15:355:41
1212.15:355:41
1312.15:355:40
1412.15:345:39
1512.15:345:38
1612.15:345:38
1712.05:345:37
1812.05:345:36
1912.05:345:36
2012.05:345:35
2112.05:345:34
2212.05:345:34
2312.05:345:33
2412.05:345:32
2512.05:345:32
2612.05:345:31
2711.95:345:30
2811.95:345:30
2911.95:345:29
3011.95:345:29

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.96 kWh/m².

For context, solar energy here swings from a low near 4.47 kWh/m² to a high of 6.56 kWh/m² in March across the year — September's 4.96 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.1Bright
35.1Bright
45.1Bright
55.1Bright
65.1Bright
75.1Bright
85.1Bright
95.1Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
165.0Bright
174.9Bright
184.9Bright
194.9Bright
204.9Bright
214.9Bright
224.8Bright
234.8Bright
244.8Bright
254.8Bright
264.8Bright
274.8Bright
284.7Bright
294.7Bright
304.7Bright
Planning a trip in September

Hazard calendar for Liberia

In seasonPeak

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

Liberia's monsoon runs August–October, when most of the year's rain falls.

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

Is September a good time to visit Liberia?

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

3.1
Sightseeing
12th-best month of the year
4.2
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Liberia.

What to pack for Liberia in September

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

In September, Liberia sees daytime highs around 29°C and nights near 22°C. Pack light clothes and rain gear. Worth having: sun protection. About 26 days see rain.

light clothesrain gearsun protection

Sea temperature near Liberia 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 20 km away) is warmest in May at about 29°C and coldest in February 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
Mar27Warm
Apr29Tropical
May29Tropical
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct28Tropical
Nov28Warm
Dec27Warm

UV index in Liberia 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 Liberia peaks around March 19 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 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 19UV 14Dec 15UV 9
UV index (midday)Level
Jan11Extreme
Feb13Extreme
Mar14Extreme
Apr13Extreme
May13Extreme
Jun13Extreme
Jul12Extreme
Aug13Extreme
Sep12Extreme
Oct12Extreme
Nov10Extreme
Dec9Very high

Air quality in Liberia 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 Liberia is worst in July — around 20 µg/m³ PM2.5 (moderate), about 3.2× the cleanest month (December, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1619 µg/m³Dec 176 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb9Good
Mar11Good
Apr19Moderate
May19Moderate
Jun16Moderate
Jul20Moderate
Aug16Moderate
Sep12Good
Oct9Good
Nov7Good
Dec6Good
Location & terrain

Where is Liberia?

Liberia sits at 10.6°N, 85.4°W, 148 m above sea level, in Costa Rica. The nearest listed city is Cañas, 44 km away.

CañasSan JoséNicoyaTamarindoMonteverdeSan Juan del SurLa FortunaSan Carlos

Topography around Liberia

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

Within 3 km, the terrain around Liberia has only modest variations in elevation — a maximum elevation change of 109 m around an average of 151 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 726 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,977 m.

The land around Liberia is covered by grassland (38%), trees (35%) and artificial surfaces (24%) within 3 km, trees (57%) and grassland (37%) within 16 km, and trees (46%) and water (32%) within 80 km.

3 km
109 m
16 km
726 m
80 km
1,977 m
treesgrasslandcroplandartificial surfaceswatermangroves
September weather nearby: Cañas 44 km · San José 48 km · Nicoya 54 km · Tamarindo 58 km · Monteverde 78 km · San Juan del Sur 83 km · La Fortuna 89 km · San Carlos 90 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 Liberia (10.6352°, -85.4378°, elevation 148 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).