Lethem weather in September

In September, Lethem sees average daytime highs of 31°C and overnight lows near 23°C, with 157 mm of rain across 18.8 wet days and about 12 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 31% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 06 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is Lethem's 1st-clearest and 9th-windiest month. For the whole year in context, see Lethem's year-round climate.

Daytime high
31°
4th warmest
Overnight low
23°
7th coldest
Rainfall
157 mm
18.8 wet days
Daylight
12 hours
5:53 AM – 5:54 PM
Cloud cover
57%
1st clearest
Wind
7 km/h
9th windiest
Solar energy
5.64 kWh/m²
Travel score
3.5
out of 10

Lethem is Regional Capital of Alto Tcutu-Upper Essequibo, which is controlled by Guyana and claimed by Venezuela.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical September day in Lethem reaches about 31°C in the afternoon and slips back to 23°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 33°C. Set against its neighbours, September runs about 1°C warmer than August and about 1°C cooler than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13122
23122
33122
43122
53122
63122
73122
83122
93122
103122
113122
123122
133122
143123
153123
163123
173123
183123
193123
203123
213123
223123
233123
243223
253223
263223
273223
283223
293223
303223

How September really feels in Lethem

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.

Lethem weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 22°469.311.84.6
Feb31° / 22°478.211.94.5
Mar32° / 23°649.3124.1
Apr31° / 23°18817.112.13.6
May29° / 22°3862712.23.2
Jun29° / 22°36728.412.23.1
Jul29° / 22°36328.912.23.2
Aug30° / 22°26125.412.13.3
Sep31° / 23°15718.8123.5
Oct32° / 23°11516.411.93.5
Nov32° / 23°11415.611.83.5
Dec31° / 23°7513.611.84.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 27% of September, with mostly cloudy or overcast conditions the remaining 43%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15743
25842
35743
45842
55842
65941
75842
85842
95842
105644
115644
125644
135644
145644
155644
165644
175644
185743
195743
205743
215743
225842
235842
245941
255941
265941
275842
285842
295941
305941

Chance of precipitation in September

Any precipitation

Lethem gets around 157 mm of rain over 18.8 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 63% and peaks near 70% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
170
270
369
469
569
669
769
869
968
1068
1167
1266
1365
1464
1564
1663
1762
1861
1960
2059
2158
2257
2357
2456
2556
2655
2755
2854
2954
3054

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 90% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Humid (%)Muggy (%)Oppressive (%)
10397
20397
30397
40496
50496
60496
70595
80595
90595
100694
110694
120793
130793
140892
150892
160991
1701090
1801090
1901189
2001189
2101288
2201387
2301486
2401585
2511584
2611683
2711782
2811881
2911980
3012079

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 7 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
126calm
136calm
146calm
156calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 06 min at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over September. Sunrise moves from 5:57 AM to 5:49 AM, and sunset from 6:01 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.15:576:01
212.15:576:00
312.15:566:00
412.15:566:00
512.15:565:59
612.05:565:59
712.05:555:58
812.05:555:58
912.05:555:57
1012.05:555:57
1112.05:545:56
1212.05:545:56
1312.05:545:55
1412.05:545:55
1512.05:535:55
1612.05:535:54
1712.05:535:54
1812.05:525:53
1912.05:525:53
2012.05:525:52
2112.05:525:52
2212.05:515:51
2312.05:515:51
2412.05:515:50
2512.05:515:50
2612.05:505:49
2712.05:505:49
2812.05:505:49
2912.05:505:48
3012.05:495:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.64 kWh/m².

For context, solar energy here swings from a low near 3.83 kWh/m² to a high of 5.74 kWh/m² in October across the year — September's 5.64 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.5Bright
125.6Bright
135.6Bright
145.6Bright
155.6Bright
165.6Bright
175.7Bright
185.7Bright
195.7Bright
205.7Bright
215.7Bright
225.7Bright
235.8Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
Planning a trip in September

Hazard calendar for Lethem

In seasonPeak

None of Lethem's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Lethem's monsoon runs April–August, 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 Lethem?

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

3.5
Sightseeing
6th-best month of the year
5.3
Beach & pool
7th-best month of the year

September is a weaker month for outdoor sightseeing in Lethem.

What to pack for Lethem in September

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

In September, Lethem sees daytime highs around 31°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 19 days see rain.

light clothesrain gearsun protection

UV index in Lethem 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 Lethem peaks around March 21 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 16 at about 11 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 21UV 15Jul 16UV 11
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar15Extreme
Apr15Extreme
May13Extreme
Jun12Extreme
Jul11Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec11Extreme

Air quality in Lethem 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 Lethem is worst in April — around 20 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (August, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateApr 920 µg/m³Aug 2110 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar20Moderate
Apr20Moderate
May14Moderate
Jun12Moderate
Jul11Good
Aug10Good
Sep11Good
Oct12Good
Nov12Moderate
Dec13Moderate
Location & terrain

Where is Lethem?

Lethem sits at 3.4°N, 59.8°W, 0 m above sea level, in Guyana. The nearest listed city is Boa Vista, 115 km away.

Boa VistaCantáMucajaíPacaraimaAlto AlegreSanta Elena de UairénCaracaraíRorainópolis

Topography around Lethem

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

Within 3 km, the terrain around Lethem has only modest variations in elevation — a maximum elevation change of 23 m around an average of 87 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 832 m; within 80 km, large variations in elevation — a maximum elevation change of 1,000 m.

The land around Lethem is covered by grassland (79%) within 3 km, grassland (85%) within 16 km, and grassland (68%) and trees (30%) within 80 km.

3 km
23 m
16 km
832 m
80 km
1,000 m
treesshrubsgrasslandartificial surfacesbare terrainwaterwetland
September weather nearby: Boa Vista 115 km · Cantá 123 km · Mucajaí 161 km · Pacaraima 190 km · Alto Alegre 196 km · Santa Elena de Uairén 200 km · Caracaraí 227 km · Rorainópolis 278 km

Guyana travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type A / B / D / G
240 V · 60 Hz
Prices
≈ 33% of US
price level, 2025
GDP per capita
$32,414
2025
Happiness
6.0 / 10
World Happiness, 2011
Safe drinking water
67%
of population, 2024
Homicide rate
19.1
per 100k, 2023
Road deaths
22.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 35%Hindu 25%other Christian 21%Roman Catholic 7%

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 Lethem (3.3726°, -59.7997°, elevation 0 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).