Holtsville (NY) Temperature by Month

The average annual maximum temperature in Holtsville, New York State, United States of America is 16°C (61°F), with daytime highs ranging from 4°C (39°F) in February to 28°C (82°F) in July. This page covers monthly averages, day-night differences, and how Holtsville compares to cities worldwide.

With significant temperature fluctuations, Holtsville enjoys distinct seasons year-round. Nighttime lows range from 20°C (68°F) in July to -4°C (25°F) in February.

The chart below illustrates the average maximum day and minimum night temperatures in Holtsville 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:

Holtsville's average annual maximum temperature is 16°C (61°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.

Glasgow, Scotland averages 13°C (55°F) a year, mild but often grey, with cold winters and rarely hot summers.

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.

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 Holtsville, February is the coolest month, with average highs of 4°C (39°F) and humidity around 59%, considered moderate. In July, the warmest month, temperatures average 28°C (82°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.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Holtsville this rarely lasts long on the ground.

For more on Holtsville's weather, including monthly rainfall, sunshine hours, and humidity, visit our Holtsville climate page.