Thank goodness for cool nights

[Scott]

I have been away from home, but everyone has been talking about how hot it has been.   On the plus side, our temperatures quickly cool once the sun goes down.  It was 96 a few hours ago, but I'm sitting at a cool 42 now.

 

So far this month, our average high has been 93.2 at the official weather station, but the average low has been 41.7, an average difference of  51.5 degrees.  Also, it is usually colder at night at the house than in town, where the weather station is located, so we get even more of a cool down.

 

The weather is sometimes difficult here in winter, but I do like it when it quickly cools off in the summer.

 

http://images.summitpost.org/original/1002822.JPG

[Black Hole]

Its amazing it can cool off that much there. Is this typical of your general area or just your valley?

[Scott]

Its amazing it can cool off that much there. Is this typical of your general area or just your valley?

 

It is typical for the valley bottom locations in this region on clear days and nights with low humidity.

 

Parts of  Idaho, Wyoming, Utah, Nevada, Oregon, and California (and other states) also have similar cool offs in some valleys.  

 

In your area, some of the valleys on the east side of the Wasatch Range have pretty similar cool downs (places such as Heber, Morgan, Huntsville, Echo Reservoir, Coalville, etc.).

 

In Utah though, Ibapah is king for anywhere populated when it comes to diurnal temperature changes:

 

https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?utibap

 

Thistle was even more so (average July high of 90 and average low of 42!), but the period of record was too short and the town doesn't exist anymore (the 1983 landslide and flood took the town out).

 

Delta Utah has gone from the low 40's to low 100's on occasion.  Places like Loa, Panguich, and the towns in the Uinta Basin can have some pretty good swings as well. 

 

Peter Sinks has some incredible diurnal changes as well, but of course no one lives there.  

[Guest happ]

Yesterday's readings aren't the best examples considering surrounding stations minimums were only 10+ warmer. But during winter minimums below freezing can occur on the same day maximums exceed 90F.

 

SAN PASQUAL VALLEY 255 :  100 /  62 /  0.00 /
RAMONA AIRPORT    1393 :  102 /  66 /  0.00 /
 

[Scott]

When it's cloudy, it doesn't cool off as fast.  It is cloudy right now and at 10:07 PM, it is still 72.   It has dropped since the 95 this evening, but on a clear night it would be into the 50's by now.   Thus far this year, the warmest official night was 52 recorded back on June 7, but since it is cloudy we might come close to beating that tonight.

 

It don't like nights to be that warm, but if it is cloudy, I hope it rains.  We haven't had any measurable precipitation since June 7, which is unusual for us.  

[Scott]

57 last night, by far the warmest night of the year so far.  Ugh!

[luminen]

When it's cloudy, it doesn't cool off as fast.  It is cloudy right now and at 10:07 PM, it is still 72.   It has dropped since the 95 this evening, but on a clear night it would be into the 50's by now.   Thus far this year, the warmest official night was 52 recorded back on June 7, but since it is cloudy we might come close to beating that tonight.

 

It don't like nights to be that warm, but if it is cloudy, I hope it rains.  We haven't had any measurable precipitation since June 7, which is unusual for us.  

 

57F is about our normal low this time of year. But you haven't had measurable precip since June 7th? That is very surprising. 

[Scott]

But you haven't had measurable precip since June 7th?

 

 

A few hours after I wrote that, it rained 0.09 inches, but it has been really dry.

[WeatherArchive]

Lots of low 50s/high 40s this summer in the valley of the jolly. A low of 48F for two hours was netted when the mercury slid after 2AM from 58F

[Phil]

You don't have to brag about it 24/7.

[Scott]

You don't have to brag about it 24/7.

 

It's always good to look for something positive about the climate.  Cool summer nights is one thing.   It can snow here 10 months out of the year or dip below -50.   There isn't much of a Spring or Fall here, or so it seems.   It's snowing one day then all of the sudden it's in the 90's.   It stays hot for a few months and then goes back to snow and cold.  

[Phil]

It's always good to look for something positive about the climate. Cool summer nights is one thing. It can snow here 10 months out of the year or dip below -50. There isn't much of a Spring or Fall here, or so it seems. It's snowing one day then all of the sudden it's in the 90's. It stays hot for a few months and then goes back to snow and cold.

That's something I'd probably enjoy. At least relative to the summers we get here, where the heat index will hover between 95 and 105 degrees every day (occasionally hitting 110-120+ degrees), and lows struggle to drop below 80 degrees.

 

It's so humid right now that my iPhone screen fogs up instantly when I walk outside. I couldn't even use the AC in my car today because the windows were fogging up like a bathroom mirror.

 

I can't believe people survived here before AC was invented.

[Phil]

The only upside to this swamp climate (in the summer) is the relatively frequent severe weather, particularly wet microbursts, of which the ingredients are almost always present thanks to the Appalachian mountains sitting upwind (tough this has been a historically pathetic severe weather year, haha).

 

As a result of the aforementioned, this area holds the world record for the strongest non-tornadic wind speed measured in a thunderstorm (158mph) and the most rainfall ever recorded within 1-minute (something like 1.26"). Otherwise, this climate is nothing but a sweaty mess from July - September.

[Phil]

Just saw this article published in the WaPo. Interesting.

 

https://www.washingtonpost.com/news/capital-weather-gang/wp/2017/07/11/a-look-back-at-pre-air-conditioned-washington/?utm_term=.db609cf4c7e7

[Guest happ]

Just saw this article published in the WaPo. Interesting.

 

https://www.washingtonpost.com/news/capital-weather-gang/wp/2017/07/11/a-look-back-at-pre-air-conditioned-washington/?utm_term=.db609cf4c7e7

 

I live in a house built in 1910 that includes a porch sleeping room on the north side of the house. Swamp coolers were very common in California due to relatively dry summers.

[Anti Marine Layer]

When I was a kid, Southern California usually had cool summer evenings (typically in the low to mid 60s not long after sunset), but they are becoming less common now. End of June had a few cool evenings, however, but sea surface temperatures have warmed up recently. Although not as bad as the East Coast, our summers are becoming more humid. In 2015, we had evening temperatures in the mid 70s well into October, but that was the very strong El Nino that brought us almost no rain.

[Scott]

That's something I'd probably enjoy. At least relative to the summers we get here, where the heat index will hover between 95 and 105 degrees every day (occasionally hitting 110-120+ degrees), and lows struggle to drop below 80 degrees.

 

It's so humid right now that my iPhone screen fogs up instantly when I walk outside. I couldn't even use the AC in my car today because the windows were fogging up like a bathroom mirror.

 

I can't believe people survived here before AC was invented.

 

Our heat indexes are lower, but surprisingly perhaps our average July high is higher than places like Baltimore or DC.  Our nights average 20 degrees colder though.

 

It isn't humid here very often, but if it ever is it kind of sucks since most people don't have air conditioning.   A few have swamp coolers, but not that many since if there is a hole in your house, it's going to let the cold weather in during winter!

[Phil]

Our heat indexes are lower, but surprisingly perhaps our average July high is higher than places like Baltimore or DC. Our nights average 20 degrees colder though.

 

It isn't humid here very often, but if it ever is it kind of sucks since most people don't have air conditioning. A few have swamp coolers, but not that many since if there is a hole in your house, it's going to let the cold weather in during winter!

What is your maximum average high? Our 21st century average high peaks around 90-92*F in mid/late July, which wouldn't be too bad except dewpoints usually hover between 70-75*F.

 

I can easily handle a dry 90-95*F without breaking a sweat. You barely even feel it unless it's at/above 100*F, so I'd still move there so long as the humidity is low during heatwaves.

[Scott]

What is your maximum average high? Our 21st century average high peaks around 90-92*F in mid/late July, which wouldn't be too bad except dewpoints usually hover between 70-75*F.

 

I can easily handle a dry 90-95*F without breaking a sweat. You barely even feel it unless it's at/above 100*F, so I'd still move there so long as the humidity is low during heatwaves.

 

I'd have to calculate it manually for just the 21st century.  

 

For the 30 year average, July 19-July 26 averages a high of 89.  The average low for those dates is 47, making that the hottest time of year.

 

It looks like for the official station in Baltimore (for example), the highs peak out at 88 between July 9 and July 17 (with an average low of 67), so it's still interesting that we're slightly warmer on average during the day than places like Baltimore, but much colder at night.

 

As far as due points here, the past two days have been humid by our standards, which means dew points approaching the 60's, which is unusual and short lived.   On clear summer days, the dew points are often in the teens.

 

Anyway, as far as humidity goes, I guess the worse places I have been are Bankok and Medan (Indonesia).   I have seen it foggy while in the 90's there.  After spending a few weeks around Medan, Singapore actually felt pleasant.  

 

I did my military training in Missouri.   It was pretty nasty since we had no air conditioning, but it is probably worse near the coast.

[Phil]

[DareDuck]

[Phil]

Quite interesting that you always seem to be the hottest or coldest location in your region during an extreme event.

Nope, but during the day locations right along the Fall Line will maximize the heat and dewpoint. We cool down better at night compared to both DCA and BWI.

 

If you doubt anything I say, here's the data streaming from my station. Baseless hyperbole isn't necessary.

 

https://www.wunderground.com/personal-weather-station/dashboard?ID=KMDBETHE62#history

[epiceast]

Fell into the 40's first time in a few weeks last night. Best sleep in weeks!

[WeatherArchive]

Nope, but during the day locations right along the Fall Line will maximize the heat and dewpoint. We cool down better at night compared to both DCA and BWI.

 

If you doubt anything I say, here's the data streaming from my station. Baseless hyperbole isn't necessary.

 

https://www.wunderground.com/personal-weather-station/dashboard?ID=KMDBETHE62#history

I don't doubt it one bit. ANY place cools off faster outside of Reagan Airport. Bad spot for an official weather station.

[Phil]

I don't doubt it one bit. ANY place cools off faster outside of Reagan Airport. Bad spot for an official weather station.

I definitely agree with you. It's the worst location imaginable.

[Swayseeker]

Vegetation has a high emissivity (close to that of a blackbody) so it can lose heat fast. But if there is material with high heat content (rocks, big trunks of trees, etc) it takes longer to cool down. Hillsides lose the energy by radiating and the air immediately above the ground then becomes cool and moves down the slope. With clouds and high relative humidity the sky temperatures is higher and you get more downwelling radiation (there is a formula, or rather there are formulas for the downwelling radiation) which keeps everything warmer. A leaf, with its high emissivity and low heat content can cool rapidly by radiating and often dew will form on leaves.

[Jesse]

They are over for the western lowlands. No more sub-55 lows until sometime in mid-October.

[WeatherArchive]

They are over for the western lowlands. No more sub-55 lows until sometime in mid-October.

What changed between then and now?

[Jesse]

What changed between then and now?

The nights got a little warmer.