In a year that’s felt like a marathon, perhaps it is fitting that many of Washington’s most notable weather happenings stretched out over a lengthy period.

It was persistently warmer and wetter than normal, but the year featured more than its share of beautiful blue skies thanks to historically low levels of air pollution.

If you like winter, you were out of luck, as 2020 brought the least snow of any calendar year on record.

The summer heat was punishing at times, and when it rained, it poured — with a record number of days with at least two inches of water.

But, all in all, the region was spared from particularly extreme or destructive weather. There were no blizzards, no triple-digit highs, no extreme cold snaps and no derechos. And by the time tropical storms reached us from the Gulf of Mexico or Atlantic Ocean in the late summer and fall, they were a shell of their former selves.

Considering the extreme weather that plagued other parts of the country, 2020 could have been a whole lot worse in Washington.

A winter without much winter

The winter months of January through March were practically snowless. Following a January that delivered only 0.2 inches in Washington (as measured at Reagan National Airport), in February all three local airports recorded nothing for the first time on record. As winter closed, the 0.6 inches in Washington, most of it falling in December the previous year, ended up the third least ever recorded.

It was warm, too. The winter finished seventh warmest on record. Flowers were much more numerous than snowflakes pretty much from start to finish.

In lieu of snow, there were some spring storms. On Feb. 7, five tornadoes touched down amid the largest wintertime severe weather outbreak on record locally.

The lack of snow is thus far continuing into the current winter. With just a trace of snowfall having fallen in December in Washington (at National Airport), 2020’s total accumulation of 0.2 inches will mark the lowest calendar year total on record.

A July full of 90s

While June and August were only a touch hotter than average, a punishing 28 of 31 days in July reached 90 degrees or higher. That’s the most of any month on record since 1872, surpassing 25 in July 2011.

We began the month with 15 straight 90-degree days, part of a 20-day streak that started in late June. It ended up as the second-longest streak of 90-degree days on record. Only 1980 and 1988 saw more, with 21 each.

July ended up as Washington’s third-hottest month on record, with an average temperature of 83.9 degrees. Including 2020, the seven hottest Julys on record have all occurred since 1990, and five of the top seven since 2010.

So much clean air, except when it was smoky

One big positive of 2020 has been the breathable air.

Recent air quality improvements are part of a long-term trend resulting from ever-stricter pollution controls. But, in 2020, the pandemic and stay-at-home orders reduced energy demand and the number of cars on the road, further suppressing pollution.

The year ended up seeing the most “good” (code green) air quality days on record.

According to Ryan Stauffer, an air pollution specialist at NASA, Wednesday should mark the 313th “good” air quality day in Washington.

Though the air was generally clean, we did see smoke waft into our skies from the Western wildfires back in September. The primary impact locally was hazy skies and intensified sunsets and sunrises.

A top 10 wettest year on record

Nearly five inches of rain have fallen this December, more than two inches above average, a fitting close for a year that will rank among the top 10 wettest on record. It comes just two years after the wettest year on record in 2018.

This year’s 57.34 inches of rain (so far) is enough for the seventh most on record. We could still surpass 1948, ranked sixth (with 57.54 inches), depending on how much rain falls New Year’s Eve.

All but three months (March, May and June) featured above-normal rainfall, resulting in a surplus of close to 18 inches compared with the annual average of 39.74 inches.

We aren’t alone here. A big chunk of the Eastern U.S. saw a very wet year.

A number of tropical systems contributed to the high rainfall totals. The biggest impact came from Tropical Storm Isaias in early August, which caused one fatality in the region, in addition to several tornadoes and daily rainfall records.

Isaias delivered the first tropical storm warning for the area since Irene in 2011. The remnants of storms Delta and Zeta also passed by the region in October, each unleashing heavy rainfall.

Among the rainiest of the days in 2020, seven produced at least two inches. This set a new annual record, surpassing six in 1886 and 1878. Even the very rainy 2018 had only five such days.

Increases in intensity and frequency of heavy rain events, and years with heavy rainfall totals, are expected in a warming world.

A probable third-warmest year

With an average annual temperature of around 60.6 degrees, 2020 will finish 2.4 degrees warmer than normal. That’s enough for a probable tie for third-warmest on record.

Nine months in 2020 were warmer than average. The warm months were quite a bit more above average than the cold months were below average.

The coldest reading of 22 degrees during the winter months perhaps set the tone. It has stood all year as 2020’s lowest temperature and will best 21 in 1949 as the warmest low temperature Washington has ever observed in a calendar year.

Summer nights were persistently warm, with the temperature failing to fall below 70 for a record 50 straight days between late June and mid-August.

This year becomes the ninth since 2010 to rank among the top 12 warmest on record. The entire top five is now made up of recent years.

Much like the increases in precipitation, these warming trends are expected and ongoing thanks to climate change.

Jason Samenow contributed to this report.