From the Wunderground Almanac for KSJC, the San Jose California Airport:
Temperature Today Average Historical Range High 72 °F 80 °F / 27 °C 66 to 101 °F / 38 °C Low 54 °F 58 °F / 14 °C 51 to 70 °F / 21 °C Precipitation Rain 0.07 in 0.00 in / 0.0 cm 0.00 to 0.00 in / 0.0 cm Snow 0 in - - to - Humidity High Dew Point 54 °F 58 °F / 14 °C 49 to 66 °F / 19 °C Low Dew Point 52 °F 51 °F / 11 °C 41 to 60 °F / 16 °C Wind Speed 7 mph 6 mph / 10 km/h 1 to 13 mph / 21 km/h
The day is still young, the clouds are still here, and drops are still in the air, so that number could rise, but as of now we’ve got 0.07 inches of rain. Yeah, 7/100 inch is not a whole lot. BUT, look at those OTHER numbers. Hard Zero all across.
It is quite bizarre to have this much cloud cover and ANY rain drops at all in the end of June.
We’ve been having a “every couple of weeks” dip into the “Cold Side Of The Jet Stream” as a Rossby Wave passes by.
You can see that in this monthly graph from Wunderground:
Oddly, just a bit up the freeway at Moffett Field NAS, it’s a bit cooler. So I’m left wondering why KSJC is where all the local stations send you when you ask for the history of THAT station, but instead get the hot International Airport history… (Wunderground seems to have instituted the policy of hiding the history from anywhere that isn’t an airport. The better to prevent anyone from demonstrating just how much Airport Heat Island is contaminating our temperature records lately…)
If you open those two and align them as a ‘blink’ between them, you get the interesting spectacle of two very large air fields, both just a tiny ways from The Bay, both just a couple of miles from each other, and yet the San Jose International is clearly hotter. Just look at the where the “normal” lines run and you can see that.
If you go about 25 miles south, but about the same distance from the ocean and with the winds blowing in from about the same direction (but clearly with at least a couple of stronger gusts) you some to Salinas. A small “farm town” airport. It is significantly cooler than KSJC.
I’ve looked at this “up down and sideways” and it sure looks to me like SJC has a bit warmer “cold nights” than the nearby non-airport stations. Wunderground won’t let me have their history, so I can’t demonstrate it with their graphs ( I’ll need to learn how to make graphs from other data to do that. Perhaps NOAA, perhaps another source). But frankly, it’s pretty clear that the International Airport is one of the hotter places around for trying to take the temperature of the place, and that it is strongly biased to warmer (especially when compared to the cow fields of 1950. When taking glider lessons just north of SJC we had to watch out for cows in the emergency landing field just off the end of the runway… That gliderport is now gone and the whole place is a sea of tarmac and asphalt roofing…)
But that aside, we’ve got something interesting going on with the weather when it’s raining, however slightly, in San Jose, at the airport, at the end of June.
When it is sprinkling here, it is often raining just a bit further north.
Guess that Mayan “Rain in 2012” glyph has some truth to it ;-)