Monthly weather averages & travel planning

Africa › 🇹🇿 Tanzania › Zanzibar
Updated: March 2026
September is a avoid time to visit Zanzibar (3/10). Average highs of 30°C and 4 sunshine hours daily make conditions workable, though not exceptional. September suits travellers visiting for indoor culture, food, and architecture rather than outdoor activities. Pack accordingly for 12 potential rain days. October offers a similar profile at lower hotel rates if dates are flexible. The main practical note: Zanzibar's popular sites are busiest between 10am and 3pm regardless of season. Arriving at opening time or after 4pm makes a significant difference to the experience. Planning tips: most accommodation categories have availability, and last-minute deals are common. The quieter streets and shorter queues can make this a genuinely enjoyable time to visit for the right type of traveller. Budget-conscious visitors will find the best value of the year in this period.
Visiting Zanzibar in September means warm daytime temperatures peaking at 30°C. Factor in 12 potential rainy days and 82% average humidity when planning your daily activities.
30°C
86°F
Avg High
23°C
73°F
Avg Low
12 days
140 mm total
Rain Days
4h
per day avg
Sunshine
82%
Humid
Humidity
The 7°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. At 82% humidity, the 30°C daytime high feels 2-4°C warmer in practice: quick-dry fabrics and shade-seeking between noon and 3pm are the sensible response. UV index averages 6 this month, classed as moderate. Sunscreen is a sensible precaution for extended outdoor time, particularly at midday. Wind averages 15 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 86°F average high, 73°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Packing for Zanzibar in September means dressing for 30°C days and 23°C evenings. A lightweight linen or cotton shirt with loose-fit trousers or a sundress handles the 30°C daytime heat. Evening temperatures settle at 23°C, a modest 7°C drop that a light cardigan or denim jacket covers. For footwear, breathable walking sandals work for casual exploration, but closed-toe trainers are better for uneven surfaces in the historic centre. A compact foldable umbrella weighs almost nothing and earns its keep across 12 potential rainy days. At 82% average humidity, quick-dry synthetic or bamboo fabrics dry overnight and stay comfortable longer than cotton.
Local tip: Layers are more practical than a single heavy garment in Zanzibar. The day-to-evening temperature shift rewards packing a versatile mid-layer you can add or remove as conditions change.
September has no major festivals or public holidays in Zanzibar, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
Based on 30°C average highs and 12 rainy days
In September, Zanzibar sits in the dry season corridor, as the ITCZ shifts away from the region and trade winds bring drier, more stable air. This produces reliably sunny days reaching 30°C, with lower humidity than the wet months. Overnight lows of 23°C offer a pleasant reprieve from the midday heat. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate, wear sunscreen. UV 6-7: High, hat and SPF 30+ essential. UV 8-10: Very High, limit midday exposure. UV 11+: Extreme, seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry, skin and throat may feel parched. 40-60%: Comfortable, ideal for most people. 60-80%: Sticky, light breathable fabrics recommended. Above 80%: Muggy, heat feels more intense; quick-dry clothing is essential.
Zanzibar in September
September ranks 7th sunniest of the year in Zanzibar, with an average 4 daily sunshine hours. The driest months are June, May, and July. January is the hottest month (32°C avg high); May is the coolest (28°C). From here, temperatures rise 1°C into October. Compared to last month (August: 29°C high, 9 rain days), September is warmer and wetter. September sits in the middle of the annual sunshine ranking for Zanzibar, offering a reasonable balance of good weather and manageable crowds.
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 32°C | 25°C | 17 | 7h | View |
| February | 31°C | 24°C | 15 | 6h | View |
| March | 30°C | 23°C | 12 | 4h | View |
| April | 29°C | 22°C | 9 | 2h | View |
| May | 28°C | 21°C | 7 | 1h | View |
| June | 28°C | 21°C | 6 | 1h | View |
| July | 28°C | 21°C | 7 | 1h | View |
| August | 29°C | 22°C | 9 | 3h | View |
| September | 30°C | 23°C | 12 | 4h | View |
| October | 31°C | 24°C | 15 | 6h | View |
| November | 32°C | 25°C | 17 | 7h | View |
| December | 32°C | 25°C | 18 | 7h | View |
January
17 rain days, 7h sun
February
15 rain days, 6h sun
March
12 rain days, 4h sun
April
9 rain days, 2h sun
May
7 rain days, 1h sun
June
6 rain days, 1h sun
July
7 rain days, 1h sun
August
9 rain days, 3h sun
September
12 rain days, 4h sun
October
15 rain days, 6h sun
November
17 rain days, 7h sun
December
18 rain days, 7h sun
Data Sources for Zanzibar
Climate normals represent 30-year averages (1991-2020). Individual years may vary.