The final freeze of the season, the last time temperatures dip to 32 degrees or lower in spring, is closely watched by gardeners. It marks the unofficial start of planting season, signals that winter’s grip is loosening, and often sets the stage for pollen, petals and patio weather.
But as with most things in DC weather, location matters. Around the city, the average last freeze is in late March but it holds off until mid- to late April in DC's colder suburbs.
D.C. vs. Dulles: urban areas warm faster
At Reagan National Airport, D.C.'s official weather observing site and a good proxy for downtown and river-adjacent neighborhoods, the average last freeze occurs on March 24.
That’s because of the same factors that delay the first freeze in fall:
- The urban heat island effect
- The moderating influence of the Potomac River
- Low elevation near sea level
Spring sunshine strengthens quickly by late March, and once mild air masses start winning out over Canadian cold fronts, freezes become harder to sustain in the city.
At Washington Dulles International Airport, representing the colder suburbs, the average last freeze typically comes more than 3 weeks later than at National, on April 19.
| Location | Average last freeze | Earliest last freeze | Latest last freeze |
|---|---|---|---|
| Reagan National Airport | March 24 | February 27, 2010 | April 21, 1956 |
| Dulles Airport | April 19 | March 25, 1986 | May 22, 2002 |
Why spring freezes are tricky
Spring freezes behave differently than fall freezes.
In autumn, it's trending steadily colder. In spring, we’re in a tug-of-war. Warm spells can surge temperatures into the 70s in March, encouraging early blooms. Then a late-season cold front barrels in and delivers a sharp overnight chill.
The classic last-freeze setup looks like this:
- A strong cold front clears the region
- Dry air moves in
- Winds relax overnight
- Clear skies allow rapid radiational cooling
Even if the daytime high hits 60, the next morning can still flirt with freezing under ideal cooling conditions.
Spring freezes can be especially damaging when they follow a stretch of warm weather that accelerates plant growth. These so-called “false springs,” followed by sharp cold snaps, have led to costly impacts for farmers. In 2026, multiple late freezes in April after a fast greenup in March, tied to abnormally warm weather, resulted in heavy damage to the apple and peach crop and vineyards in northwest Virginia.
The growing season divide
The span between the last spring freeze and the first fall freeze defines the growing season. And in th DC area, that season is meaningfully longer in the city than in outlying areas.
Urban gardeners often plant earlier, sometimes successfully, sometimes nervously. Suburban gardeners tend to wait until mid- to late April to feel more confident. Some outside the Beltway even hold off until Mother's Day each year to be safe.
It’s not just elevation and distance from downtown. Local topography matters, too. Low-lying backyards and open rural fields cool more efficiently than built-up neighborhoods. Microclimates can mean a difference of 5 to 10 degrees over just a few miles.
Has the last freeze been occurring earlier?
As the region’s climate has warmed, the average last freeze has gradually shifted earlier. Warmer late-winter temperatures make it less likely that strong cold air masses can sustain freezing conditions deep into spring.
Five decades ago, the final freeze was about 10 days later than it is today. Around 1900, the final freeze typically came during the second week of April. Before weather observations were moved from DC to National Airport, the latest final freeze occurred on April 29, 1874.
But recent trends don't mean April or even May freezes don't happen. As recently as 2016, the final freeze in DC occurred on April 11 and, in 2013, it happened on May 14 at Dulles. So, late freezes are still possible — just less frequently than previously.
When considering that the first freeze in the fall has shifted earlier, the typical season from first to last freeze has shrunk from roughly 160 days around 1900 to less than 125 days today.
The same general trends are occurring at Dulles Airport.
Ian Livingston contributed to this report.
