Above average July and it’s all relative
July 28th, 2012 at 10:03 pm by Tara Hastings under Weather
Today felt fantastic! In the sun it felt hot however we had many clouds and that allowed for a little relief. What I did notice is our high temperature today was below normal. This is something we haven’t seen too much this July. I did some digging and found many of July’s high temperatures were not only above normal but well above normal.
Only 5 days have been at or below normal! Of course let’s not forget the two days in the triple digits. I’m sure many of you remember and hope they don’t come back. Dayton is now 6.7° above normal for the month. I’m not sure where we rank as far as warmest July’s – however I do know that 6.7° is a big number. We’ll have to wait and see how we end up and if this July tops the charts. Even if it doesn’t this is one summer I’m sure many of us won’t forget.
One other weather event we lacked in July is rain. Many farmers had to and are still dealing with problems due to a lack of rain.
The first 14 days of July Dayton Int’l Airport had only a drop in the bucket. However while this is the official reporting station there were several scattered storms that produced significant rain across the Miami Valley. We’ve picked up a bit more and are now sitting just below three inches. Even though we’re making progress Dayton is still almost an inch below normal for the month.
The recent rain has helped out with the Drought Monitor.
The “severe” drought is much smaller than it had been weeks before. We have a couple chances for rain next week so maybe this will fade even farther. It’s nice to see the lawns greening up a bit across the area.
I wanted to explain something that was brought up to me by a man today at the Celtic Festival. He told me he wished all of the meteorologists (not just me apparently) would use humidity rather than dew point to explain how it feels outside. I tried to explain to him the difference but he was set in his ways we both got frustrated with each other because we wouldn’t budge on our viewpoints. So I’m taking this opportunity to explain the difference between the two.
We often use a map like this on the air:
Dew point is the measurement of how much moisture is in the air. The higher the dew point the more humid or “sticky” it feels outside. A general rule of thumb is if the dew point is 65 or higher it’s going to feel humid. A dew point of 70 is uncomfortable. So when you see a map like this and there is no green or just a light shade of green it’s comfortable.
The relative humidity percentage you see and hear is not directly related to the comfort factor you feel. For example if there is a relative humidity of 90% in the winter time it doesn’t feel humid does it? Relative humidity gives us an idea how close the air is to saturation. RH is a ratio between the amount of water in the air and the maximum amount of water possible at a certain temperature. So we can have a relative humidity of 90% and it doesn’t feel humid. Right now the temperature is 73°, the dew point is 63 and the relative humidity is 71% and it feels comfortable outside. If the dew point were higher it would feel sticky but if the relative humidity were higher it may not.
Confused? Ok – here’s the deal. Basically the dew point is a much better indicator of how uncomfortable it will feel when you step outside. If it’s above 65 you’ll feel uncomfortable. However I can’t say that if the relative humidity is above 90% it will feel uncomfortable because that’s not the case. I can see why some people want the relative humidity because we ask “Is it humid outside?” not “Is it dewy outside?”
