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Kenya Meteorological Department

MAM RAINFALL CLIMATOLOGY

MAM 2025 RAINFALL OUTLOOK

MAM 2025 ONSET

MAM TEMPERATURE OUTLOOK

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Kenya Meteorological Department

  • March to May (MAM) is Kenya’s major rainfall season (long rains), influencing much of equatorial Eastern Africa.

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  • The Lake Victoria Basin, Highlands West of the Rift Valley, and both the Central and South Rift Valley typically see the highest rainfall amounts, often exceeding 300mm.

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  • The Highlands East of the Rift Valley (including Nairobi County) and the Coastal Strip also receive significant rainfall, shaping the season's impact across the country.

MARCH-APRIL-MAY (MAM) “LONG-RAINS” SEASON LTM/CLIMATOLOGY

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Kenya Meteorological Department

  • The national consolidated forecast The MAM 2025 forecast shows near to above-average rainfall over the Lake Victoria Basin, South Rift Valley, Highlands West of the Rift Valley, southern Southeastern Lowlands, and northern Northwestern Kenya.

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  • Near to below-average rainfall is expected over the Central Rift Valley, Highlands East of the Rift Valley (including Nairobi County), most of Northwest Kenya, Coastal region, Southeastern Lowlands, and some areas of the Highlands West of the Rift Valley.

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  • Below-average rainfall is expected over the northeastern regions and the north coast.

CONSOLIDATED RAINFALL OUTLOOK FOR MAM 2025

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Region

Onset Dates

Cessation

Distribution

1

Counties in the Lake Victoria Basin, South Rift Valley and some parts of the Highlands West of the Rift Valley):

(Homa Bay, Migori, Kisumu, Busia, Siaya, Narok, Bomet, Kisii, Nyamira, Kericho, Nandi, Kakamega, Vihiga,)

Rainfall continues from February with occasional dry spell

Continues to June

Good

2

Counties in Central and North Rift Valley and parts of the Highlands West of the the Rift Valley (Nakuru, Baringo, Western parts of Laikipia, Elgeyo Marakwet, Uasin Gishu, Trans Nzoia, Bungoma and Southern parts of West Pokot)

Rainfall in February followed by dry spell till the 4th week of March to 1st week of April)

Continues to June

Poor to Fair

3

Highlands East of the Rift Valley including

Nairobi County: (Nyeri, Kirinyaga, Murang’a, Embu, Meru, Kiambu, Nyandarua, Nairobi and eastern parts of Laikipia)

Occasional rainfall in February followed by a dry spell. Onset expected during the 4th week of March to 1st week of April

3rd to 4th week of May

Fair

4

Southeastern Lowlands (Kajiado, Kitui, Makueni, Machakos, Tana River and Taita Taveta),

Occasional rainfall in February followed by a dry spell. Onset expected during the 4th week of March to 1st week of April

3rd to 4th week of May

Poor to Fair

5

North Coast region (Lamu, Coastal parts of Tana River, and Northern parts of Kilifi)

2nd to 3rd week of April

Continues into June

Poor

6

South Coast region (Mombasa, Kwale and Southern parts of Kilifi)

4th week of March to 1st week of April

Continues into June

Poor to Fair

7

The Northwest (Turkana, Samburu) and the Northern parts of West Pokot)

Occasional rainfall in March. Onset expected during the 1st to second week of April

Undefined

Poor

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The Northeast (Wajir, Isiolo, Garissa, Mandera and Marsabit)

1st to 2nd week of April

Undefined

Poor

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ONSET DATES

Rainfall continues from February with occasional dry spell

Rainfall in February followed by dry spell till the 4th week of March to 1st week of April)

Occasional rainfall in February followed by a dry spell. Onset expected during the 4th week of March to 1st week of April

2nd to 3rd week of April

4th week of March to 1st week of April

Occasional rainfall in March. Onset expected during the 1st to second week of April

1st to 2nd week of April

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Kenya Meteorological Department

Warmer than average temperatures are expected over the whole country, with increased probabilities over the Central Kenya, Southeastern Lowlands, South Coast, and parts of Northeast

CONSOLIDATED TEMPERATURE OUTLOOK FOR MAM 2025

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Kenya Meteorological Department

Download the Statement��https://drive.google.com/drive/folders/1vJX5sPVNfCaPj8Vr7hZESoWL6FT7fkot?usp=drive_link

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Kenya Meteorological Department