Climate and average weather in Semi

In Semi, the weather is oppressive, hot, wet, and partly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around June.

Best: early January to late February

Over the course of the year, the temperature in Semi typically varies from 24°C to 29°C, and is rarely below 24°C or above 29°C. April is the hottest month of the year, while August is the coldest.

Based on the travel score, the best times of year to visit Semi for warm-weather activities are from early January to late February and early December to late December.

Hottest
Apr
29°
Coldest
Aug
24°
Wettest
Jun
259 mm
Driest
Jan
21 mm
Rain / yr
1087 mm
184 wet days
Daylight
11.6–12.4 h
shortest–longest
Elevation
8 m
6.4°N
Clearest
Dec
36% cloud

Semi weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early January to late February.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Semi, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

Temperatures in Semi stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 29°C and low of 27°C; the coolest is August, with an average low of 24°C and high of 25°C.

Days typically run about 1°C warmer than nights year-round.

18°20°22°24°26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2826
Feb2827
Mar2927
Apr2927
May2827
Jun2726
Jul2625
Aug2524
Sep2625
Oct2726
Nov2827
Dec2827

How hot and cold Semi really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Semi feels like about 35°C (around April 6). About 174 days a year carry some heat stress, peaking in April.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan32282626
Feb33282727
Mar35292727
Apr35292727
May34282727
Jun29272526
Jul26262525
Aug25252424
Sep26262525
Oct28272626
Nov32282727
Dec33282727

Average hourly temperature in Semi

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on April afternoons, near 29°C, and coldest before dawn in August, near 24°C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Semi weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 26°216.611.77.1
Feb28° / 27°277.811.86.4
Mar29° / 27°4812.5125.3
Apr29° / 27°7315.712.14.8
May28° / 27°16423.412.34.0
Jun27° / 26°25926.112.43.9
Jul26° / 25°13218.912.35.2
Aug25° / 24°7313.312.26.1
Sep26° / 25°10518125.2
Oct27° / 26°11020.211.95.0
Nov28° / 27°4913.811.75.7
Dec28° / 27°277.611.66.9

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Semi gets about 1087 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 3.4 months, from around Apr 14 to Jul 25, peaking in June at about 88% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 26.

June is the wettest month by volume, with 259 mm over about 26 wet days; January is the driest, with 21 mm.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 13 · 88%Dec 26 · 17%
Rain on a day (%)Rain days
Jan227
Feb288
Mar4013
Apr5216
May7523
Jun8626
Jul6219
Aug4313
Sep6018
Oct6420
Nov4714
Dec258

Monthly rainfall

Over a full year, Semi collects about 1087 mm of rain across 184 wet days — roughly 91 mm in an average month.

It doesn’t fall evenly. June is the wettest month with 259 mm, while January is the driest at just 21 mm. The three wettest months alone bring about 51% of the year’s total.

050100150200250300JanFebMarAprMayJunJulAugSepOctNovDec21274873164259132731051104927
Rainfall (mm)Rain days
Jan217
Feb278
Mar4813
Apr7316
May16423
Jun25926
Jul13219
Aug7313
Sep10518
Oct11020
Nov4914
Dec278

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Semi, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around October 21 and lasts for 4.8 months, ending around March 15. The clearest month is December, when the sky is clear, mostly clear, or partly cloudy 78% of the time on average.

The cloudier part of the year begins around March 16 and lasts for 7.2 months, ending around October 20. The cloudiest month is June, when it is overcast or mostly cloudy 78% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecDec 21 · 82%Jun 4 · 18%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan6733
Feb5941
Mar4456
Apr3565
May2773
Jun2278
Jul2476
Aug2872
Sep2971
Oct4258
Nov6634
Dec7822

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 5, brings about 12 h 24 min of light; the shortest, around January 1, only 11 h 36 min — a swing of roughly 0 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.77:096:49
Feb11.87:106:58
Mar12.07:006:58
Apr12.16:466:54
May12.36:376:54
Jun12.46:397:01
Jul12.36:457:05
Aug12.26:477:00
Sep12.06:436:45
Oct11.96:396:30
Nov11.76:446:26
Dec11.66:576:35

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Semi averages about 8 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 21 days.

The sunnier stretch runs 4.6 months, from around Oct 24 to Mar 11. The sunniest month is December, with roughly 19 sunny days (bright).

The greyest month is July, down near 2 sunny days — about 90% fewer than the December peak.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedbrightbrilliantDec 2121 daysJul 112 days
Sunny daysSky
Jan16Bright
Feb11Mixed
Mar8Gloomy
Apr6Gloomy
May4Gloomy
Jun2Gloomy
Jul2Gloomy
Aug3Gloomy
Sep3Gloomy
Oct7Gloomy
Nov14Mixed
Dec20Bright

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

Semi is humid all year round — on a typical day the air feels at least humid, and there is no real dry season to wait for.

The stickiest month is February, when it feels muggy, oppressive or miserable about 99% of the time. Even in January, the mildest month, the air is dry or comfortable only 1% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressive
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan1452071
Feb011989
Mar000298
Apr000298
May0002179
Jun0008218
Jul001990
Aug001990
Sep000991
Oct0008317
Nov0003961
Dec0122572

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Semi is typically light breeze, near 18 km/h, and varies moderately with the seasons.

The windier part of the year lasts 3.3 months, from around Jun 18 to Sep 24. The windiest month is July, averaging about 22 km/h (breezy).

The calmer part of the year runs from around Sep 25 to Feb 4, with November the calmest month at about 15 km/h.

051015202530JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezebreezywindyJul 31 · 23 km/hNov 2 · 14 km/h
Wind speed (km/h)Feels
Jan17light breeze
Feb19light breeze
Mar20breezy
Apr19light breeze
May17light breeze
Jun18light breeze
Jul22breezy
Aug22breezy
Sep19light breeze
Oct16light breeze
Nov15light breeze
Dec15light breeze

Hazard calendar for Semi

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

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

Semi sees seasonal dust haze (January–April), heaviest in February.

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

Best time to visit Semi

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Semi throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid February, Semi is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best times of year to visit Semi for general outdoor tourist activities run from late July to late August and again from early December to late February, with a peak score in the last week of December.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationDec 28 · 7.5

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan7.1good
Feb6.4good
Mar5.3fair
Apr4.8fair
May4.0fair
Jun3.9fair
Jul5.2fair
Aug6.1good
Sep5.2fair
Oct5.0fair
Nov5.7good
Dec6.8good

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Semi for hot-weather activities is from mid November to late March, with a peak score in the last week of December.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationDec 24 · 8.0

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Semi, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

Semi packs about the same all year — highs hold near 29°C. Across the year the things worth having are light clothes, rain gear, sun protection and a windbreaker.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In April, Semi sees daytime highs around 29°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 16 days see rain.

Sea temperature near Semi

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea offshore is warmest in May at about 29°C and coldest in August near 25°C.

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

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Warm
Feb28Tropical
Mar29Tropical
Apr29Tropical
May29Tropical
Jun28Warm
Jul26Warm
Aug25Warm
Sep26Warm
Oct27Warm
Nov29Tropical
Dec28Tropical

UV index (midday) in Semi by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Semi peaks around April 10 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeExtremeVery highApr 10UV 13Dec 19UV 8
UV index (midday)Level
Jan8Very high
Feb10Very high
Mar12Extreme
Apr13Extreme
May11Extreme
Jun11Extreme
Jul11Extreme
Aug10Very high
Sep12Extreme
Oct12Extreme
Nov9Very high
Dec8Very high

Average hourly UV index in Semi

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in April the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 6 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan74.5
Feb7.55
Mar86
Apr86
May85.5
Jun85.5
Jul7.55.5
Aug7.55
Sep86
Oct7.55.5
Nov74.5
Dec6.53.5

Air quality in Semi by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Semi is worst in January — around 78 µg/m³ PM2.5 (unhealthy), about 7.7× the cleanest month (September, 10 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyModerateGoodModerateJan 1676 µg/m³Sep 1810 µg/m³
PM2.5 (µg/m³)Level
Jan78Unhealthy
Feb61Unhealthy
Mar28Moderate
Apr24Moderate
May15Moderate
Jun15Moderate
Jul16Moderate
Aug13Moderate
Sep10Good
Oct12Good
Nov19Moderate
Dec61Unhealthy
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Semi is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Semi banks about 6,071 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around March.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan525
Feb489
Mar556
Apr537
May540
Jun488
Jul469
Aug452
Sep457
Oct503
Nov518
Dec537

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Semi receives about 5.0 kWh/m² a day of solar energy — bright — and it stays remarkably steady, holding between 4.2 and 5.6 kWh/m² all year. For solar panels, output here is a flat line, not a seasonal wave.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmoderatebrightintenseApr 15.6 kWhJun 264.2 kWh
Solar energy (kWh/m²)Level
Jan5.4Bright
Feb5.6Bright
Mar5.6Bright
Apr5.5Bright
May4.9Bright
Jun4.2Bright
Jul4.3Bright
Aug4.6Bright
Sep4.7Bright
Oct4.9Bright
Nov5.0Bright
Dec5.2Bright

Where is Semi?

Semi sits at 6.4°N, 2.6°E, 8 m above sea level, in Benin. The nearest listed city is Ekpé, 9.0 km away.

Topography around Semi

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

Within 3 km, the terrain around Semi has only modest variations in elevation — a maximum elevation change of 13 m around an average of 3 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 30 m; within 80 km, only modest variations in elevation — a maximum elevation change of 171 m.

The land around Semi is covered by water (45%) and grassland (22%) within 3 km, water (58%) within 16 km, and water (37%) and trees (34%) within 80 km.

3 km
13 m
16 km
30 m
80 km
171 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
Nearby: Ekpé 9.0 km · Porto-Novo 15 km · Adjarra 19 km · Avrankou 21 km · Missérété 22 km · Cotonou 22 km · Ganvié 27 km · Badagry 30 km

Benin travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
220 V · 50 Hz
Prices
≈ 34% of US
price level, 2025
GDP per capita
$1,658
2025
Happiness
4.4 / 10
World Happiness, 2025
Safe drinking water
18%
of population, 2024
Homicide rate
1.1
per 100k, 2017
Road deaths
26.8
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
Very low
EF EPI 406
Religion
Muslim 28%Roman Catholic 26%Protestant 14%Vodoun 12%

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 Semi (6.3667°, 2.6167°, elevation 8 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).