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Heating Season in New York

New York City typically opens its heating season around October 8 and closes it around May 14. Here is the full window, the rest of New York, how cold the nights get, and any active National Weather Service cold product.

Typical heating season at New York City: October 8 to May 14
Heating degree days (New York City)
4,553
Typical opening
Oct 8
Days of heating season
218
Nights 32 F or below
67

New York's heating season

1991-2020, New York City
Today
The bar spans the median opening to the median closing at New York City. Half of years open earlier than the left edge and half close later than the right, so treat it as the middle of the distribution rather than a boundary. An opening is the first day of the season's first run of 7 or more consecutive days that accrue heating degree days.
September 26
Early years
open by here, 1 year in 10
October 8
Median opening
the 50/50 date
May 14
Median closing
the other bookend
218 days
Median span
opening to closing

New York City needs 4,553 heating degree days a year, about 70 percent of what Albany needs and 30 percent less than Buffalo, and it is the pavement doing it as much as the latitude. The city records 67.3 nights a year at or below freezing against Albany's 135.7, and its season closes on May 14 while Albany's runs to May 31. Buffalo's number is nearly Albany's, but its season is shaped by Lake Erie rather than by elevation.

City by city

Heating across New York, station by station

A single state figure would hide the thing that decides a winter: elevation, latitude and distance from water move these numbers further inside New York than three decades of warming does. Each row is one NOAA reference station. The degree days and the night counts are quoted straight from NOAA's published 1991 to 2020 normals; the opening and closing dates are our own derivation from the same agency's daily observations, because NOAA publishes no date shaped heating variable.

The spread here runs from 4,553 heating degree days a year at New York City to 6,466 at Buffalo, a difference of 1,913 inside one state.

StationHeating degree daysSeason opensSeason closesNights 32 F or belowNights 20 F or below
New York City4,553October 8May 146717
Albany6,357September 19May 3113660
Buffalo6,466September 19May 3112450

Longest heating load

6,466

heating degree days a year at Buffalo, the most of this page's New York stations.

Quoted NOAA normal

Coldest nights

60

nights a year at Albany whose low reaches 20 F or below.

Quoted NOAA normal

Coldest on record

-28 F

at Albany on January 19, 1971, in a station record running 1938 to 2026.

Our derivation
A snow covered traffic signal glowing green through blowing snow at night on Penn Avenue North in Minneapolis
Blowing snow at Penn Avenue North in Minneapolis. Official climate readings come from a standard ventilated shelter at an airport, which is usually a degree or two colder at night than the built-up neighbourhoods a few miles away, so a city thermometer and a station normal are describing slightly different winters. “Minneapolis Winter Snow Storm (24162463023)” by Tony Webster, CC BY-SA 2.0
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How far the nights fall

The nights set the load, the days only ease it

A heating degree day is built from the daily mean, which means the overnight low is doing half the arithmetic. Two places can share an afternoon high and part company completely after dark, and the one whose nights fall further pays for it in every hour before sunrise, when there is no sun on the walls and nothing to slow the loss.

In New York, Albany averages 60 nights a year at or below 20 F, and the coldest daily maximum on record at any station here is -8 F at Albany: a day the air never rose past it. Those counts are NOAA's published normals, and NOAA's thresholds include the named value, so a night that bottomed out at exactly 20 F is counted as one.

Nights at or below 32 F

67

a year at New York City. NOAA's published 1991 to 2020 normal.

Quoted NOAA normal

Nights at or below 0 F

0.1

a year at New York City. Below zero the gap between inside and outside is more than 70 degrees, and every hour of it is heating load.

Quoted NOAA normal

Days that never thaw

16

days a year at New York City whose HIGH stays at or below 32 F. An ice day is the one where the building gets no relief at all, because even the afternoon is below freezing.

Quoted NOAA normal
Fern shaped ice crystals spread across the inside of a window pane, lit blue and amber
Ice ferns on the inside of a pane. They form where indoor moisture reaches glass cold enough to freeze it, which is a very direct picture of what a heating degree day is measuring: the size of the gap between the two sides of a wall. “Frost patterns 5” by Schnobby, CC BY-SA 3.0
Right now, from the agency

What the National Weather Service has out in New York

Everything below is read live from api.weather.gov when this page loads and is shown exactly as the issuing forecast office wrote it, with the office and the times it covers.

Live from the National Weather Service
Active cold products in New York

Checking api.weather.gov for active cold products.

Product text, issuing office, area and times are passed through exactly as the National Weather Service issued them. The NWS retired Wind Chill Warning, Wind Chill Watch, Wind Chill Advisory, Hard Freeze Warning and Hard Freeze Watch on 1 October 2024. Read . Source: api.weather.gov

Live from the National Weather Service
The next seven nights at New York City

Loading the National Weather Service gridpoint forecast.

The measure itself

What New York asks for, month by month

Heating degree days are the measure utilities and mechanical engineers plan against, and NOAA publishes them directly, so every figure in this section is NOAA's published normal. At New York City the coldest month is January, carrying 970 degree days on its own, and the months that carry real heating demand run January through December. December, January and February together account for 57 percent of the year's total, which is the number that tells you whether this is a concentrated winter or a long shallow one.

Heating degree days by month at New York City, quoted from NOAA's published 1991 to 2020 normals. One heating degree day is one degree of daily mean temperature below 65 F, added up, so the bars show how much heating the calendar actually asks for rather than how cold any single night got.

“The base temperature we use is 65°F. If the mean temperature is above 65°F, we subtract the base temperature (65°F) from the mean, and the result is Cooling Degree Days (CDD). If the mean temperature is below 65°F, we subtract the base temperature from the mean, and the result is Heating Degree Days (HDD).”

U.S. Energy Information Administration, Degree days

“A cooling degree day indicates a hot day and measures how much air conditioning we need to keep a building cool. A heating degree day indicates a cold day and measures how much heating we need to keep a building warm.”

U.S. Energy Information Administration, Degree days

NOAA's 1991 to 2020 normals publish, without any arithmetic of ours: annual and monthly heating degree days, the mean number of nights a year at or below 32 F, 20 F and 0 F, and the mean number of days whose high never rises above 32 F. NOAA publishes no date shaped heating variable, so the opening and closing dates on this page are this site's own derivation, labelled as such.

One caveat. Adding up daily heating degree days from the raw observations does not reproduce NOAA's published normal exactly: NCEI derives its degree-day normals from smoothed daily temperature normals with an adjustment for how days scatter around the mean, and it estimates days a station missed, while this site sums the days that reported and drops incomplete years. The two land about a percent apart in either direction, which is why the degree day figures here are always NOAA's.

Our summary of information published by NOAA NCEI 1991-2020 U.S. Climate Normals

An ornate cast iron column radiator painted silver, standing against a dark red wall on a tiled floor
A cast iron radiator in a nineteenth century house in Uptown New Orleans, which is the point of showing it: New Orleans needs 1,176 heating degree days a year and its heating season is only about 105 days long, and it still built houses with radiators in them. A short season is not the same as no season. “RadiatorColumns” by Infrogmation, CC BY 2.5
What the agencies say

Cold weather, in the agencies' own words

Cold safety guidance is the National Weather Service's. Here it is on the cold itself, quoted directly, and then the products it issues about it.

“Extremely cold air comes every winter into at least part of the country and affects millions of people across the United States. The arctic air can be dangerous. Combined with brisk winds, dangerously cold wind chill values can result. People exposed to extreme cold are susceptible to frostbite and can succumb to hypothermia in a matter of minutes.”

National Weather Service, Cold Weather Safety

“Hypothermia occurs when the body loses heat faster than it can produce it.”

National Weather Service, Cold Weather Safety

“A freeze occurs when the temperature drops below 32°F. Freezes and their effects are significant during the growing season. Frost develops on clear, calm nights and can occur when the air temperature is in the mid-30s.”

National Weather Service, Cold Weather Safety

On 1 October 2024 the National Weather Service retired five product names in its hazard simplification work. Wind Chill Warning became Extreme Cold Warning, Wind Chill Watch became Extreme Cold Watch, Wind Chill Advisory became Cold Weather Advisory, Hard Freeze Warning was folded into Freeze Warning, and Hard Freeze Watch became Freeze Watch. The agency's own announcement is at weather.gov. It matters here because code still asking for a retired name gets an empty answer, which looks identical to an all clear. The panel above asks only for the current five.

Carbon monoxide: the agencies, in their own words

Heating season is carbon monoxide season. The guidance below is the EPA's, verbatim, and the full guidance lives with the EPA and with the Consumer Product Safety Commission.

“Carbon monoxide is an odorless, colorless and toxic gas. Because it is impossible to see, taste or smell the toxic fumes, CO can kill you before you are aware it is in your home. The effects of CO exposure can vary greatly from person to person depending on age, overall health and the concentration and length of exposure.” (US EPA, Carbon Monoxide's Impact on Indoor Air Quality)

On what exposure does, again the EPA: “At low concentrations, fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, impaired vision and coordination; headaches; dizziness; confusion; nausea. Can cause flu-like symptoms that clear up after leaving home. Fatal at very high concentrations.”

And on generators, which is where a cold snap and a power cut meet: “Never use a portable generator inside homes, garages, crawlspaces, sheds or similar areas. Deadly levels of carbon monoxide can quickly build up in these areas and can linger for hours, even after the generator has shut off.”

Full guidance: EPA Carbon Monoxide and indoor air quality and CPSC Carbon Monoxide Information Center. The EPA and the CPSC are the authorities on carbon monoxide, detectors and heating equipment, and their guidance is the guidance.

Split firewood stacked under an open sided wooden shed while snow falls in the dark behind it
A woodshed filling up before the season. How anyone heats a building is their own decision, and the number every one of those decisions rests on is how many degree days the year is likely to ask for, which is what this page carries. “Firewood shed in winter (Unsplash)” — Ryan Graybill — CC0
Where these numbers come from

How the New York figures are calculated

Two registers, kept apart. Quoted: the heating degree days and the counts of cold nights and ice days are NOAA NCEI's published 1991 to 2020 U.S. Climate Normals, printed here as NOAA publishes them. Derived: the opening and closing dates, the season span and the record extremes are ours, computed from NOAA NCEI GHCN-Daily station observations, because the normals product publishes no date shaped heating variable at all.

The rules are the same at every station. A heating day is a day that accrues at least one heating degree day under NOAA's own whole-degree convention. A season runs July to June, labelled by its starting year, because every US heating season crosses New Year. The season opens on the first day of its first run of 7 or more consecutive heating days and closes on the last day of its last such run; 7 days is this site's threshold, stated on every page, because one cold morning in August does not open a heating season and a week that never averages above 65 F does. A season only counts if at least 85 percent of its days carry a clean pair of readings, and incomplete seasons are excluded rather than filled in. Where a percentile lands on a season that never sustained a heating run at all, no date is printed.

The cross check: NOAA publishes counts of nights at or below 32 F, 20 F and 0 F, and this site computes its own from the daily records with the same inclusive rule. At New York City the derived count is 67 against NOAA's 67 freezing nights, and across all 150 stations in this dataset 145 agree within two days a year. The same counts also agree within 1.2 days everywhere against the frozen pipes vertical, which computes its 20 F counts independently over a different season window. One detail matters if you try to reproduce this: a US station reports whole degrees Fahrenheit and NOAA's day count normals include the threshold itself, so a night recorded at exactly 20 F counts here as it does for NOAA, and requesting the archive in metric would quietly lose it.

The page's shape follows those numbers. Where a state's primary station needs 6,000 heating degree days a year or more, the dates carry little information and the page leads with length and cold instead. Where it needs under 2,000, leading with dates would oversell the season. New York is on the defined shape, at 4,553 degree days.

Live conditions come from api.weather.gov, read in your browser at page load. Sources: NOAA NCEI 1991-2020 U.S. Climate Normals, NOAA NCEI GHCN-Daily, EIA Degree days. All are US Government works in the public domain.

Broken ice floes covering the Chicago River between downtown buildings, with the Wells Street Bridge behind
Ice on the Chicago River below the Wells Street Bridge. Thirty years of daily observations is enough to describe a normal winter and nowhere near enough to predict next week. Once you are inside the season, the forecast takes over from the climatology, which is what the live panel above is for. “Frozen Chicago River” by Codo, CC BY-SA 2.0
Common questions

New York heating season FAQ