L.A. recorded its hottest February on record

March 01--It was supposed to be one of the wettest Februaries on record. Instead, by one measure at least, it became the hottest on record.

With an average high temperature of 77.5, February was almost two degrees hotter than the previous record set in 1954, according to a Times analysis.

Monday's reported high of 74 capped a 10-day spell of temperatures in the 70s and 80s. Those mild but unusually warm days combined with the two record heat spells earlier in the month to lift February 2016 into the lead, according to a Times analysis of weather data going back to 1878. The National Weather Service was withholding its official announcement until midnight Monday to include another measure using a combination of high and low readings.

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Applying Monday's predicted low of 56 to that measure, The Times found that February would become the second warmest with a high-low average of 65.9, falling just four-tenths of a degree below the record set in 1995.

But the month's meager showing of rain, just over three-quarters of an inch, was extreme only in contrast to the expectations of El Ni񯮠This February ranks as the 37th driest. In the 137 years of National Weather Service records there have been seven Februaries with no rain at all, the first in 1885 and most recently 1984.

The two hot spells in the month, when downtown temperatures shot into the high 80s, were not unusual in themselves. Despite the flurry of record days early in the month, February did not produce any unusual streaks of hot days. There were similarly two heat spells in February of 1954, but between them the temperatures dropped below normal.

Heat records fell on the 8th, 9th and 15th and 17th downtown Los Angeles: a total of four record days but no streaks longer than two days. During that period, records also fell at UCLA and in the San Fernando Valley, creating the perception of nearly a week of consecutive hottest days, when, in fact, no single station broke records more than two consecutive days.

From the long view, those streaks were not especially striking. It's not unusual, for example, for heat records to fall on three consecutive days.

A Times analysis of National Weather Service records going back to 1877 shows that there have been 18 streaks of at least three days of record heat in downtown Los Angeles.

One of those streaks was in an earlier February. For four days, from Feb 1 through Feb. 4, 1995, the highs downtown reached 88, 94, 94 and 91, all but one hotter than the hottest day this month.

The streak of streaks occurred in April of 1989. From the 4th through the 8th, the temperatures were all records: 100, 105, 106, 100 and 92.

Like sports stats, record hot days and streaks can be engaging, but they don't necessarily mean a lot.

They speak as much to the variability of the weather as any trend.

"The atmosphere is chaotic and has a certain randomness to it," said Nicholas A. Bond, a research meteorologist at the University of Washington.

In that regard, the no-show of the El Ni񯠲ains was no more surprising than the summer heat.

"All this is kind of--in mathematical terms--a probabilistic thing," Bond said. "It's not like El Ni񯠤ictates these weather patterns. It just favors certain types rather than other types."

As might be expected, more historic temperatures fall in the latter half of the 20th century, reflecting the warming of the climate. The 1980s and the '90s have the highest number of record hot days.

However, even though average temperatures have inexorably climbed over the last three decades, the year with the most record days was 1971. with 13.

There could be many reasons for that, said Kevin E. Trenberth, distinguished senior scientist with the National Center for Atmospheric Research.

Even though all the readings are at the same location, the USC campus, the location itself could have changed, Trenberth said.

"How has the exposure changed? "Trenberth asked. "Where are the nearest freeways and sources of pollution? Construction typically has an urban heat island effect, mainly keeping things warmer at night, but also keeping things drier and so less evaporative cooling. Shading keeps thing cooler. Air conditioning might warm things up outside."

Among all possible variables, smog might be the most obvious. It was much thicker in the 1970s than it is today.

"The pollution may affect fog or clouds," Trenberth said. "All of those things matter for records. "

doug.smith@latimes.com

ryan.menezes@latimes.com