Old Jamestown in Summer

In summer (June, July and August), Old Jamestown sees average daytime highs around 86°F and overnight lows near 68°F, with 10.5 in of rain over about 30 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.

Over the season highs climb from about 81°F in early June to 85°F by late August. The sky is clear or mostly clear about 39% of the time across summer, and the air most often feels muggy.

Summer is Old Jamestown's 3rd-best season to visit on our travel score. For the whole year in context, see Old Jamestown's year-round climate.

Avg daytime high
86°F
warmest season of the year
Avg overnight low
68°F
Rainfall
10.5 in
30 wet days
Avg wind
6 mph
Travel score
5.1
3rd-best season
Months
Jun · Jul · Aug

Temperature in Old Jamestown in Summer

Average highAverage lowShaded bands: 10–90% of days

Over the season highs climb from about 81°F in early June to 85°F by late August.

A typical summer day in Old Jamestown reaches about 86°F and drops to 68°F overnight. The warmest of the three months is July, the coolest June.

60°80°100°JunJulAug

How summer really feels in Old Jamestown

Once humidity and wind are folded in, summer brings about 23 days that feel above 90°F and 0 that feel at or below 32°F.

Days feeling ≥ 90°F
23
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Old Jamestown weather by month

How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 24°2.88.22.99.60.0
Feb44° / 28°2.57.72.810.50.8
Mar55° / 37°3.710.51.411.73.5
Apr66° / 47°4.611.20.2135.8
May75° / 58°5.013.5014.16.2
Jun84° / 67°4.211014.75.4
Jul87° / 70°3.49.9014.44.7
Aug86° / 68°2.99.2013.55.2
Sep79° / 60°3.37.6012.37.1
Oct67° / 48°3.48.40.1116.6
Nov54° / 37°3.68.60.89.93.4
Dec43° / 29°2.68.22.29.30.6

Cloud cover in Summer

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time across summer.

0%25%50%75%100%JunJulAug

Chance of precipitation in Summer

Any precipitation

Old Jamestown gets around 10.5 in of rain over 30 wet days across summer. The line is the day-by-day chance of measurable precipitation.

0%10%20%30%40%50%JunJulAug

Humidity in Summer

DryComfortableHumidMuggyOppressiveMiserable

Most of summer feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

0%25%50%75%100%JunJulAug

Wind in Summer

Winds average 6 mph across summer.

0246810JunJulAug

Sunrise & sunset in Summer

DaylightNight

Daylight runs from about 14 h 30 min in early June to 12 h 54 min by late August. The lit band spans sunrise to sunset each day.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJunJulAug

Solar energy in Summer

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day across summer, about 6.2 kWh/m².

0246JunJulAug
Planning a trip in summer

Hazard calendar for Old Jamestown

In seasonPeak

In summer, Old Jamestown overlaps its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Old Jamestown sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is summer a good time to visit Old Jamestown?

Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.

5.1
Sightseeing
3rd-best month of the year
6.9
Beach & pool
1st-best month of the year

summer is a reasonable time to visit Old Jamestown for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Old Jamestown in Summer

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

In summer, Old Jamestown sees daytime highs around 86°F and nights near 68°F. Pack light clothes and sun protection. Worth having: rain gear. About 30 days see rain.

light clothessun protectionrain gear

UV index in Old Jamestown in Summer

LowModerateHighVery highExtreme

Clear-sky midday UV across summer averages around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Old Jamestown peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 23UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Old Jamestown in Summer

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.

Air quality in Old Jamestown is worst in August — around 18 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodAug 1018 µg/m³Oct 228 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar13Moderate
Apr11Good
May14Moderate
Jun16Moderate
Jul18Moderate
Aug18Moderate
Sep13Moderate
Oct8Good
Nov9Good
Dec10Good
Location & terrain

Where is Old Jamestown?

Old Jamestown sits at 38.8°N, 90.3°W, 568 ft above sea level, in United States. The nearest listed city is Florissant, 3.7 mi away.

Topography around Old Jamestown

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Old Jamestown.

Within 2 miles, the terrain around Old Jamestown has only modest variations in elevation — a maximum elevation change of 210 ft around an average of 531 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 636 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 801 ft.

The land around Old Jamestown is covered by trees (54%) and grassland (21%) within 2 miles, trees (38%) and cropland (26%) within 10 miles, and trees (43%) and cropland (43%) within 50 miles.

2 miles
210 ft
10 miles
636 ft
50 miles
801 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Summer weather nearby: Florissant 3.7 mi · Spanish Lake 5.0 mi · Ferguson 6.2 mi · Hazelwood 6.2 mi · Alton 6.8 mi · Upper Alton 8.7 mi · Godfrey 9.9 mi · Overland 9.9 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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 Old Jamestown (38.8349°, -90.2851°, elevation 568 ft), 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.