Newark weather in September

In September, Newark has daytime highs averaging 24 °C, nights around 16 °C, with 8.9 wet days, and a sea temperature of 21 °C. Figures are 1991–2020 climate normals.

  1. Jan -1°
  2. Feb
  3. Mar
  4. Apr 10°
  5. May 16°
  6. Jun 21°
  7. Jul 24°
  8. Aug 23°
  9. Sep 20°
  10. Oct 13°
  11. Nov
  12. Dec

Daily temperatures through September

11°21°30°18152229
Daily highDaily low Day of month on the horizontal axis. Highs peak at 27.1 °C and lows bottom out at 13.0 °C.

How September develops

Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.

DaysAvg highAvg lowChance of rain
1–10 September26.3 °C17.7 °C30 %
11–20 September24.3 °C15.9 °C29 %
21–30 September22.6 °C14.4 °C29 %
0%50%100%151015202530
Chance of a wet day (over 1 mm) by date in September. Wettest date over the 30 years: September 10, at 43 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical September Share of the month
Days above 25 °C 13 of 30 42 %
Days above 30 °C 2.2 of 30 7 %
Days below 0 °C 0 of 30 0 %
Days with more than 1 mm rain 8.9 of 30 30 %

Conditions in September

MeasureAverage
Mean temperature 20 °C
Record high (1991–2020) 35 °C
Record low (1991–2020) 6.4 °C
Relative humidity 74 %
Wind speed 15 km/h
Cloud cover 53 %

Where Newark ranks in September

RankingPositionValue
Places with the best weather in North America in September49thof 5089/100

September compared with the months around it

Month Avg high Rainfall Cloud
July 29.3 °C 108 mm 55 %
August 28.1 °C 105 mm 54 %
September 24.3 °C 106 mm 53 %
October 17.9 °C 101 mm 51 %
November 11.8 °C 80 mm 55 %

See all twelve months for Newark

Nearby destinations in September

Destination Avg high Wet days Sea
Newark 24 °C 8.9 21
New York City 24 °C 9 21
Staten Island 24 °C 9 21

QuestionsSeptember in Newark, answered

How warm is Newark in September?

Daily highs average 24 °C and nights fall to about 16 °C, a spread of 8.4 °C between afternoon and dawn. That makes September the 4th warmest month of the year here.

Does it rain much in Newark in September?

September averages 106 mm of rain, spread over about 9 of the 30 days — 30 % of the month. Cloud cover averages 53 % of the sky.

Is the sea warm enough to swim in September?

The sea averages 21 °C off Newark in September. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.

How long are the days in September?

Newark averages 12 hours between sunrise and sunset in September. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.

Data sources and method

Normal period
1991–2020
Dataset version
era5-1991-2020-scores1.1
Last processed

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.