The Month of July

Today’s high is predicted to be 99 degF, with no rain in the forecast through the end of the week. Well, it’s summer, of course, but some things are ridiculous.

So with that in mind, here is the summary of the month of July, for the United States and Athens, Georgia. The weather will have been more interesting in its extremes elsewhere, especially in the west. Here, it was remarkably average.

From the National Weather Service Climate Prediction Center, this is a plot of mean temperature anomalies for the US. That’s the difference in the average temperature for this July above or below the average for July over many years, plotted in colors. The anomalies are in Fahrenheit.


The cooler than normal temperatures throughout the north central US continues from May. For much of the rest of the country there was a switch in cooler and warmer temperatures, compared to June. Really warm temperatures continued to spread throughout much of the western US, except in the extreme southwest where sharply contrasting cooler temperatures were experienced.

From the (click through to the monitoring maps from the left sidebar) National Weather Service Climate Prediction Center, this is a plot of mean precipitation anomalies for the US over the month of July:


The US midsection continued its fifth month of normal to above average rainfall in July. There was some improvement in drought conditions in the southwest, including southern California, but much lower than normal rainfall otherwise persisted in central and northern California and worsened in Oregon and Washington. Much of the southeast finally received average and even slightly above average rainfall in July.

For Athens:

The above figures show that we had remarkably average temperatures rainfall during July. We had two fire calls, one 10-22’d just after I pulled out with the pumper, and the other in the wee hours of the morning of the 30th, a trailer fire.

Here is my plot of high temperatures for the month of July in Athens. As usual, the black dots are for the 17 years 1990-2006 (black dots), 2008 (green line), and 2007 (red line).


We certainly had some warm weather in July, especially during the end of the month. The high was 1.4 degF above normal, however the “average average” for the month was pretty much on target. (This means, of course, that our nights were cooler, by 2.6 degF, than normal. Now that’s interesting!) To underscore the extremes of June, July’s average high temps were cooler than June’s by 1.5 degF. However July 2008 was warmer than July of last year by 4 degF.

The average July high this year was 92.1 degF, compared to an average over 89 years since 1920 of 90.2 degF. We were more than one standard deviation above the mean high temperature on 5 days in July, compared to an average 5.4 days per July, and that’s insignificant.

I went into the rainfall situation here for the first half of the year last month and there won’t be too many dramatic changes from our experiences in July. And that’s because we actually got rain in July! The Athens report was for 3.95 inches compared to 4.41 inches, slightly below normal but an embarrassment of riches in comparison. Out here at Wolfskin we actually got 4.66 inches, considerably more than the Athens report would indicate.

Again, the green line shows our actual rainfall, the red shows the average accumulation expected. The black dots are rainfall over the last 19 years, the river of peach shows the standard deviation. We stayed right around the normal throughout the month, ending just slightly below it.



Interestingly, this year’s pattern of rain and heat is following nearly the same trend as last year. Then too we had a hot and dry June, followed by a cooler and wetter July. It was August 2007 that was the kicker, with its 105-107 degF highs for many days during the month. We’ll be sitting on pins and needles wondering if the repeat continues.

I’ll continue to link to this neat prognosticator in which you can get variously timed precipitation and temperature outlooks. Last month it promised us that we will have above average precipitation and below average temperatures for at least the first two weeks in July and in retrospect that was a pretty good prediction.

Geekstuff:
NOAA’s weekly ENSO update tells us that sea surface temperatures in the central and east equatorial Pacific have returned to ENSO-neutral regions, suggesting that we have now left La Niña, with enough time for the atmospheric conditions to have responded. NOAA expects that ENSO-neutral conditions will continue through fall 2008.

Finally, and to reiterate the link way above, NOAA has a neat State of the Climate product. By clicking on the year, such as 2007, you can get to monthly and even weekly reports and zero in on regional descriptions that are much nicer than my own.