Climate and average weather in Mersa

In Mersa, the summers are hot, dry, and mostly clear and the winters are warm and mostly clear.

Best: mid September to late December

Over the course of the year, the temperature in Mersa typically varies from 12°C to 31°C, and is rarely below 9°C or above 33°C. June is the hottest month of the year, while January is the coldest.

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

Hottest
Jun
31°
Coldest
Jan
13°
Wettest
Mar
134 mm
Driest
Jun
3 mm
Rain / yr
566 mm
79 wet days
Daylight
11.3–12.7 h
shortest–longest
Elevation
1,721 m
11.7°N
Clearest
Nov
26% cloud

Mersa 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 mid September to late December.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Mersa stay fairly even through the year, without a distinct hot or cool season. The warmest month is June, with an average high of 31°C and low of 18°C; the coolest is January, with an average low of 13°C and high of 24°C.

Days typically run about 12°C warmer than nights year-round.

10°15°20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2413
Feb2514
Mar2715
Apr2816
May3017
Jun3118
Jul3018
Aug2917
Sep2917
Oct2716
Nov2613
Dec2512

Average hourly temperature in Mersa

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 June afternoons, near 31°C, and coldest before dawn in January, near 13°C.

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

Mersa 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
Jan24° / 13°699.211.47.4
Feb25° / 14°56811.67.2
Mar27° / 15°13413.811.96.3
Apr28° / 16°9811.712.36.3
May30° / 17°234.112.56.1
Jun31° / 18°30.412.75.5
Jul30° / 18°397.712.65.3
Aug29° / 17°5910.612.45.6
Sep29° / 17°102.812.16.8
Oct27° / 16°132.911.78.0
Nov26° / 13°243.411.58.4
Dec25° / 12°384.711.38.3

Chance of rain

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

Mersa gets about 566 mm of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.

The wetter season lasts 4.2 months, from around Dec 31 to May 7, peaking in March at about 46% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jun 13.

March is the wettest month by volume, with 134 mm over about 14 wet days; June is the driest, with 3 mm.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecwetterdriermostly drysome rainoften wetvery wetMar 23 · 46%Jun 13 · 1%
Rain on a day (%)Rain days
Jan299
Feb308
Mar4314
Apr3812
May144
Jun20
Jul248
Aug3411
Sep113
Oct93
Nov113
Dec165

Monthly rainfall

Over a full year, Mersa collects about 566 mm of rain across 79 wet days — roughly 47 mm in an average month.

It doesn’t fall evenly. March is the wettest month with 134 mm, while June is the driest at just 3 mm. The three wettest months alone bring about 53% of the year’s total.

0255075100125150175JanFebMarAprMayJunJulAugSepOctNovDec695613498233395910132438
Rainfall (mm)Rain days
Jan699
Feb568
Mar13414
Apr9812
May234
Jun30
Jul398
Aug5911
Sep103
Oct133
Nov243
Dec385

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Mersa, 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 August 20 and lasts for 4.3 months, ending around December 27. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 87% of the time on average.

The cloudier part of the year begins around December 28 and lasts for 4.3 months, ending around May 6. The cloudiest month is January, when it is overcast or mostly cloudy 39% 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%JanFebMarAprMayJunJulAugSepOctNovDecSep 17 · 88%Jan 16 · 57%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearer
Clearer (%)Cloudier (%)
Jan6139
Feb6337
Mar6436
Apr7030
May7921
Jun7921
Jul6931
Aug7129
Sep8713
Oct8614
Nov8614
Dec7921

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 42 min of light; the shortest, around January 1, only 11 h 18 min — a swing of roughly 1 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.46:496:12
Feb11.66:486:24
Mar11.96:336:29
Apr12.36:146:29
May12.56:026:34
Jun12.76:016:42
Jul12.66:086:46
Aug12.46:146:37
Sep12.16:146:18
Oct11.76:145:59
Nov11.56:235:50
Dec11.36:385:57

Sunny days

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

Mersa averages about 17 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 11 and 22 days.

The sunnier stretch runs 4.3 months, from around Aug 24 to Dec 31. The sunniest month is November, with roughly 22 sunny days (bright).

The greyest month is July, down near 13 sunny days — about 38% fewer than the November peak.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergloomymixedbrightbrilliantNov 1022 daysJul 3111 days
Sunny daysSky
Jan14Mixed
Feb13Mixed
Mar13Mixed
Apr14Mixed
May19Bright
Jun19Bright
Jul14Mixed
Aug15Mixed
Sep20Bright
Oct21Bright
Nov21Bright
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.

In Mersa, the air stays dry or comfortable essentially all year. Even in March, the muggiest month, it feels humid or worse only about 14% of the time — humidity is not something you need to plan around here.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJun 6 · 100%Mar 22 · 84%humidcomfortabledryhumidcomfortablehumid
Dry (%)Comfortable (%)Humid (%)
Jan70282
Feb65305
Mar503614
Apr523414
May80173
Jun9910
Jul84142
Aug69283
Sep9280
Oct9190
Nov88111
Dec85151

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.

Wind in Mersa is steady company: average speeds sit near 6 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmJun 27 · 7 km/hJan 15 · 5 km/h
Wind speed (km/h)Feels
Jan5calm
Feb5calm
Mar5calm
Apr5calm
May6calm
Jun7calm
Jul7calm
Aug6calm
Sep6calm
Oct5calm
Nov5calm
Dec5calm

Hazard calendar for Mersa

In seasonPeak

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

Mersa's rainy season runs January–January, when most of the year's rain falls.

Mersa sees seasonal dust haze (June–August), heaviest in July.

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

Best time to visit Mersa

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late December, Mersa 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 time of year to visit Mersa for general outdoor tourist activities is from mid September to early March, with a peak score in the first week of November.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationNov 6 · 8.4

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
Jan7.4good
Feb7.2good
Mar6.3good
Apr6.3good
May6.1good
Jun5.5good
Jul5.3fair
Aug5.6good
Sep6.8good
Oct8.0ideal
Nov8.4ideal
Dec8.3ideal

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best times of year to visit Mersa for hot-weather activities run from late April to late July and again from mid August to late December, with a peak score in the third week of September.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationSep 19 · 8.7

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 Mersa, 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.

For a warm-season trip around June (highs near 31°C), the essentials are light clothes and sun protection. In the cold season around January (highs near 24°C), pack light clothes, rain gear and sun protection.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In June, Mersa sees daytime highs around 31°C and nights near 18°C. Pack light clothes. Worth having: sun protection.

UV index (midday) in Mersa 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 Mersa peaks around March 19 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 12 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 12UV 10
UV index (midday)Level
Jan12Extreme
Feb13Extreme
Mar15Extreme
Apr14Extreme
May13Extreme
Jun13Extreme
Jul11Extreme
Aug13Extreme
Sep13Extreme
Oct13Extreme
Nov11Extreme
Dec10Extreme

Average hourly UV index in Mersa

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 March the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6.5 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)
Jan7.55.5
Feb7.56
Mar8.56.5
Apr86.5
May8.56.5
Jun86
Jul86
Aug86.5
Sep86.5
Oct7.56
Nov75
Dec75

Air quality in Mersa 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 Mersa is worst in June — around 38 µg/m³ PM2.5 (poor), and holds fairly steady the rest of the year.

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorPoorModerateSep 1038 µg/m³Nov 1826 µg/m³
PM2.5 (µg/m³)Level
Jan29Moderate
Feb30Moderate
Mar32Moderate
Apr28Moderate
May33Moderate
Jun38Poor
Jul34Moderate
Aug37Poor
Sep38Poor
Oct29Moderate
Nov26Moderate
Dec28Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Mersa 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. Mersa banks about 4,210 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around June.

01,0002,0003,0004,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan259
Feb265
Mar335
Apr358
May419
Jun436
Jul437
Aug411
Sep392
Oct355
Nov284
Dec260

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.

Mersa receives about 5.9 kWh/m² a day of solar energy — bright — and it stays remarkably steady, holding between 5.2 and 6.6 kWh/m² all year. For solar panels, output here is a flat line, not a seasonal wave.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmoderatebrightintenseMay 96.6 kWhJan 135.2 kWh
Solar energy (kWh/m²)Level
Jan5.2Bright
Feb5.8Bright
Mar6.2Intense
Apr6.6Intense
May6.6Intense
Jun5.9Bright
Jul5.4Bright
Aug5.7Bright
Sep6.0Bright
Oct6.1Intense
Nov5.9Bright
Dec5.5Bright

Where is Mersa?

Mersa sits at 11.7°N, 39.6°E, 1,721 m above sea level, in Ethiopia. The nearest listed city is Weldiya, 19 km away.

Topography around Mersa

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

Within 3 km, the terrain around Mersa has significant variations in elevation — a maximum elevation change of 451 m around an average of 1,673 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,229 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,515 m.

The land around Mersa is covered by cropland (48%) and shrubs (33%) within 3 km, shrubs (41%) and cropland (37%) within 16 km, and shrubs (36%), cropland (29%) and grassland (28%) within 80 km.

3 km
451 m
16 km
2,229 m
80 km
3,515 m
treesshrubsgrasslandcroplandartificial surfacesbare terrain
Nearby: Weldiya 19 km · Sifra 41 km · Hāyk’ 41 km · Dessie 59 km · Kombolcha 66 km · Batī 66 km · Lalibela 77 km · Alamata 84 km

Ethiopia travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type C / E / F / L
220 V · 50 Hz
Prices
≈ 37% of US
price level, 2025
GDP per capita
$933
2025
Happiness
4.0 / 10
World Happiness, 2025
Safe drinking water
14%
of population, 2024
Homicide rate
8.5
per 100k, 2012
Road deaths
28.2
per 100k/yr, 2019
Income group
Low
World Bank
English
Low
EF EPI 499
Religion
Ethiopian Orthodox 44%Muslim 31%Protestant 23%other 1%

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 Mersa (11.6667°, 39.65°, elevation 1,721 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. 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).