What a month. The biggest features were the continuing unusual warmth of the nighttime lows, the warmer days and the lack of rain; both trends that continue from last winter.
I'm looking at weatherunderground's monthly calendar for Santa Ana.
Weather History for Santa Ana, CA | Weather Underground
Here are some of the noteworthy numbers:
- Despite the historical average overnight low being 46 degrees, there were only 5 days that were at 46 degrees or lower; with the lowest temperature being 40 degrees on January 1. This was the lowest temperature recorded all winter; and as it is now February with the coldest part of the year behind us, it seems at least better than 50% we will escape the winter without a temperature reading in the 30s.
- 22 of the 31 days had overnight lows above 50 degrees, with 4 of those days being above 60 and 1 being above 70. I suspect this is linked to warmer than usual offshore water temps for the second year in a row; (right now they are running 5-6 above normal) combined with a general lack of storm activity from the north. There were only 3 overnight lows in the 40s in December, so we've only had 12 total days this winter with ovenight lows in the 40s, despite the average low being around 46.
- As mentioned above, there was one overnight low exceeding 70 degrees; January 21 had a high of 84 degrees and a low of 71. That is an only once in every 5-10 years occurrence. I honestly don't know what set of factors come into play to make it happen. There have been plenty of much warmer January days; and this wasn't a very strong Santa Ana. I know the offshore water temps are 5-6 degrees above normal right now, which might play a part, but the last time I remember a 70+ night in January, the water wasn't that warm; so who knows.
- 22 of the 31 days had highs exceeding 70 degrees, with 6 of those days exceeding 80 degrees The highest high was 86 degrees, on both January 6 and 26. The average high for the month was 73 degrees. The lowest daytime high was 61 degrees, on both January 1 and 2. We now got out of both December and January without a daytime high in the 50s or below. Not typical.
- Rain was recorded on 5 days during the month, with only "trace" amounts being recorded on one of those days and "0.00" being recorded on one another. That leaves three days where measurable rain was recorded, for a total of .71 inches. Well below average the average roughly 2 inches we get.