Temperature trend lines for April, 2010-2017.
(Copyright © 2017 by Wil C. Fry. Some rights reserved.)
April 2017 was warmer than the eight-year average, but only barely. April 2012 remains the warmest April on record. This was a bit of relief, since the previous two months set all-time records for warmth.
Note that April is our “bellwether” month — April’s average HLA (high-low average) is closest to our annual average HLA. In a few specific years, October was closer to that year’s HLA.
Our high for the month was 91°F (twice), which isn’t remarkable as April goes. But our low for the month was startling at 49°F. Most previous Aprils have seen temperatures cooler than that — usually in the 30s or low 40s. Even May often sees temps cooler than 49°F. That trend held true for the entire month, with our lows being warmer than usual, which is what bumped the HLA above average, despite the highs being unremarkable.
We didn’t set any daily record lows, but recorded one daily record high early in the month.
I measured 6.69 inches of rainfall for April 2017. This is a new record, beating last April. Most of that rain fell on one day, April 11 (our fourth-rainiest day since we moved here eight years ago), and most of the remainder was on April 2. I recorded only 8 days that saw precipitation, which is slightly below average as well as below median.
1. Our combined January-thru-April HLA has never been this warm. The last time a year began with heat anywhere close to this (2012), we ended up with our warmest year of all time. That year, January through May and December all set records, three of which still stand. (This year, February and March surpassed 2012’s records.)
2. The lows from February through April are warmer than they’ve ever been, and our last freezing day was in the second week of January. All I can extrapolate from this is the continuing trend of lows in most months getting warmer. Most months, our HIGHS aren’t seeing startling rises, but it’s not getting as cool as it used to at night.
3. The last time January/February/March/April combined for so few freezing days (four) was 2012 (two), our warmest year on record.
4. The last time we started off a year this wet (15 inches in four months) was 2010, which turned out to be an average year rainfall-wise, because the second half of it was extremely dry.
All signs point to a very hot year, but also not a very dry one (overall). Our only very dry year since moving here was 2011, and that drought was already apparent the previous winter.