Sunday, August 12, 2018

Oakland temperatures in 2018

In global terms, the average temperature around the world is not as warm as any of the past three years. The first six months - marked in black with dots - is extremely similar to the first six months of 2010, the pattern in green. This would make 2018 the fourth or fifth warmest year on record with the top three years being 2016, 2017 and 2015. One of the favorite talking points of the climate change denialists for most of the 21st Century was "It's nothing compared to 1998!" The last five years have all been warmer than 1998 on average, which is represented by the light brown line that is slightly higher that the green and black patterns in February, but below those lines in every other month.

Global temperature differences for the spring months of 2018 are not completely compiled yet, and the unknown values are marked in grey. As is obvious from even the partial data, global warming is not uniform. Some places aren't showing much warming and some are even cooler than average, shown on the grid in light blue and dark blue. Even so, stories of record temperatures and sustained heat waves have been reported around the world, many listed in this July 5th story in the Washington Post.

And then there's Oakland, where the temperatures have been relatively mild in comparison with the past few years. The baseline temperature, represented by the grey dotted line is, the daily average for the period 1981-2010. While there have been heat waves up and down the West Coast this year, they have skipped over the Bay Area for the most part. The longest stretch of much warmer temperatures at the local weather station was a week in early February that could best be described as an early spring, with temperatures in the mid sixties to mid seventies. That sort of streak does not deserve the title "heat wave" in human terms, but sometimes an early warm spell can cause plants to bloom early or animals to end hibernation.

As all natives know, we are now going into the hot months here in the Bay Area. September is regularly the warmest month of the year around here, with August usually slightly warmer than July. I will post the final numbers for 2018 early next January.

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