Watertown weather in September

In September, Watertown sees average daytime highs of 68°F and overnight lows near 55°F, with 3.8 in of rain across 10.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 72°F in the first days to 64°F by the end. The sky is clear or mostly clear about 33% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Watertown's 3rd-clearest and 9th-windiest month. For the whole year in context, see Watertown's year-round climate.

Daytime high
68°
4th warmest
Overnight low
55°
9th coldest
Rainfall
3.8 in
10.1 wet days
Daylight
12 h 18 min
5:49 AM – 6:07 PM
Cloud cover
55%
3rd clearest
Wind
7 mph
9th windiest
Solar energy
4.13 kWh/m²
Travel score
6.3
out of 10

Watertown is city in Jefferson County, New York, United States.

Density
1,104/km²
people per km²
Founded
1800

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 72°F in the first days to 64°F by the end.

A typical September day in Watertown reaches about 68°F in the afternoon and slips back to 55°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 60°F and 77°F. Set against its neighbours, September runs about 7°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17360
27359
37259
47259
57258
67258
77158
87158
97157
107057
117056
127056
136956
146955
156955
166855
176854
186854
196754
206753
216753
226653
236652
246552
256551
266551
276451
286450
296350
306350

How September really feels in Watertown

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

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

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Watertown 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 (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan28° / 16°3.413.612.39.10.0
Feb29° / 16°2.8119.310.20.0
Mar37° / 24°3.212.17.411.60.1
Apr50° / 37°4.112.32.613.22.2
May62° / 48°3.4120.114.55.0
Jun71° / 59°4.012.2015.26.3
Jul76° / 64°4.213.2014.96.5
Aug75° / 62°3.812.5013.86.7
Sep68° / 55°3.810.1012.36.3
Oct56° / 44°4.613.50.310.83.5
Nov45° / 34°3.813.74.39.40.9
Dec34° / 24°3.81510.78.80.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 19% of September, with mostly cloudy or overcast conditions the remaining 47%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15842
25842
35743
45644
55644
65644
75545
85545
95446
105446
115446
125446
135446
145446
155446
165347
175347
185347
195248
205248
215149
225149
235149
245050
254951
264852
274852
284753
294654
304555

Chance of precipitation in September

Any precipitation

Watertown gets around 3.8 in of rain over 10.1 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 35% and peaks near 40% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
134
234
334
434
534
634
734
835
935
1035
1135
1234
1334
1434
1534
1633
1733
1833
1933
2033
2133
2234
2334
2435
2536
2637
2738
2839
2939
3040

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 49% of days. Sticky, muggy-or-worse air turns up on roughly 8% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1262728172
2272727172
3282726162
4302825152
5312824142
6332824142
7352823132
8362823121
9382722111
10402722101
1141272291
1243262191
1345262081
1447262071
1548251971
1651251860
1751251860
1854241750
1955241650
2056231650
2159221540
2260221440
2363211330
2464211230
2565201230
2667201120
2769191020
287019920
297218820
307517710

Wind in September

Winds average 7 mph in September.

Across September, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 90 minutes over September. Sunrise moves from 5:31 AM to 6:06 AM, and sunset from 6:35 PM to 5:40 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:316:35
213.05:336:33
313.05:346:32
412.95:356:30
512.95:366:28
612.85:376:26
712.85:386:24
812.75:406:22
912.75:416:20
1012.65:426:18
1112.65:436:17
1212.55:446:15
1312.55:456:13
1412.45:476:11
1512.35:486:09
1612.35:496:07
1712.25:506:05
1812.25:516:03
1912.15:536:01
2012.15:545:59
2112.05:555:57
2212.05:565:55
2311.95:575:53
2411.95:595:52
2511.86:005:50
2611.86:015:48
2711.76:025:46
2811.76:035:44
2911.66:055:42
3011.66:065:40

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.13 kWh/m².

For context, solar energy here swings from a low near 1.24 kWh/m² to a high of 6.2 kWh/m² in June across the year — September's 4.13 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.4Bright
104.4Bright
114.3Bright
124.3Bright
134.3Bright
144.2Bright
154.2Bright
164.1Bright
174.1Bright
184.0Bright
194.0Moderate
203.9Moderate
213.9Moderate
223.8Moderate
233.8Moderate
243.7Moderate
253.6Moderate
263.6Moderate
273.5Moderate
283.5Moderate
293.4Moderate
303.4Moderate
Planning a trip in September

Hazard calendar for Watertown

In seasonPeak

In September, Watertown sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Watertown 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 September a good time to visit Watertown?

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

6.3
Sightseeing
3rd-best month of the year
3.4
Beach & pool
4th-best month of the year

September is a reasonable time to visit Watertown for sightseeing.

What to pack for Watertown in September

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

In September, Watertown sees daytime highs around 68°F and nights near 55°F. Worth packing: rain gear. About 10 days see rain.

rain gear

Sea temperature near Watertown in September

The nearest coast averages about 68°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 24 mi away) is warmest in August at about 72°F and coldest in March near 35°F.

It's comfortable for a long swim from Jul 14 to Sep 13 — about 2 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar35Bracing
Apr38Bracing
May45Bracing
Jun58Bracing
Jul69Refreshing
Aug72Refreshing
Sep68Cool
Oct59Bracing
Nov50Bracing
Dec43Bracing

UV index in Watertown in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Watertown peaks around July 13 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 13UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5Moderate
May7Very high
Jun7Very high
Jul8Very high
Aug5High
Sep6High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Watertown?

Watertown sits at 44.0°N, 75.9°W, 466 ft above sea level, in United States. The nearest listed city is Kingston, 34 mi away.

Topography around Watertown

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

Within 2 miles, the terrain around Watertown has only modest variations in elevation — a maximum elevation change of 374 ft around an average of 486 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,260 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,205 ft.

The land around Watertown is covered by trees (50%), grassland (21%) and artificial surfaces (21%) within 2 miles, trees (53%), grassland (21%) and cropland (21%) within 10 miles, and trees (59%) and water (22%) within 50 miles.

2 miles
374 ft
10 miles
1,260 ft
50 miles
2,205 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Kingston 34 mi · Brockville 44 mi · Oswego 47 mi · Greater Napanee 55 mi · Clay 56 mi · Cicero 56 mi · Rome 57 mi · Syracuse 65 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 Watertown (43.9748°, -75.9108°, elevation 466 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).