Fairfield (NJ) Temperature by Month
The average annual maximum temperature in Fairfield, New Jersey, United States of America is 17°C (63°F), with daytime highs ranging from 4°C (39°F) in January to 30°C (86°F) in July. This page covers monthly averages, day-night differences, and how Fairfield compares to cities worldwide.
Fairfield Monthly Temperatures
The climate in Fairfield is known for significant temperature differences throughout the year. At night, this contrast is just as clear, with lows ranging from 19°C (66°F) in July to -6°C (21°F) in January.
The chart below illustrates the average maximum day and minimum night temperatures in Fairfield by month:
The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM, when the sun's heating effect is strongest. July, the warmest month, gets 271 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Fairfield vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
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Fairfield vs World: Temperature Compared
Fairfield's average annual maximum temperature is 17°C (63°F). To put that in context, here's how it compares to a few well-known destinations:
Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.
Queenstown, New Zealand averages 10°C (50°F) annually — remember seasons are flipped, so its coldest months fall in June and July.
San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation — summers are often cool and foggy, winters mild.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
What Does the Temperature Feel Like in Fairfield?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.
In Fairfield, January is the coolest month, with average highs of 4°C (39°F) and humidity around 61% — considered high. In July, the warmest month, temperatures average 30°C (86°F) with 64% humidity — conditions that feel high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.
Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.
For more on Fairfield's weather — including monthly rainfall, sunshine hours, and humidity — visit our Fairfield climate page.
