How much does summer weather affect your pace?

Don't focus on pace per mile. Just run by effort. Heat increases the difficulty of running, hence people like Benji Durden layering up to increase the training stimulus without increase pace or distance.

You'll be fitter and faster come winter with a consistent effort that doesn't focus on pace.

use this to calculate adjusted pace

https://runnersconnect.net/training/tools/temperature-calculator/

use this to calculate dew point

http://www.dpcalc.org/

Based on what the calculator says, you should be running ~ 20 seconds per mile slower. Maybe your overtrained. Maybe your body really doesnt react well to heat. If your running early in the morning when its cool out and still having trouble maybe get a blood test or try to get more sleep. Also focus on hydration, not just water, electrolytes.

NeedForSpeed wrote:

use this to calculate dew point

This just proves that the OP MAJORLY exaggerated the heat and humidity he runs in.

I'm in DC and yesterday in particular was insanely hot and humid - it was 92 degrees with really high humidity - weather report at the time said it felt like 99 degrees.

I planned on a 7 or 8 mile run, relatively easy pace (7:30 - 7:45)

At 4.44 miles at 7:40 average pace I stopped, exhausted and streaming sweat.

I agree with earlier posters, it's all about slowing the pace down, ignoring the digits on the watch, and running by feeling when the conditions are this rough. For me, that's really tough. Even on easy days following a hard effort day, when I notice the pace slowing beyond 7:45 I feel uncomfortable and compulsively push the pace.

After typing all this out I'm wondering if it's a good idea to just NOT wear a watch, or turn off the display of the pace stats as I'm running.

It's been MISERABLE for running in VA since the cool streak ended. I'm probably averaging 20-40 seconds slower per miles on my runs ever since the heat and humidity hit. The other day my shins were sweating after like 20 minutes. It'll get a little better once you've adjusted a bit, but it won't be the same as running in March/April. The good news is that it's all about effort, and when fall hits you'll feel great - slower speeds now doesn't mean you're just slow and will have to "start over" with training in the fall. Make sure you hydrate, and bring water with you on your runs even if you normally wouldn't (I don't bring water for anything shorter than 14-15 miles in the winter, but in the summer I'll bring water if I'm doing more than 6 or 7).

It's the weather. Humidity is a killer.

For the last few years I am running in the South myself. The performance goes drastically down with higher humidity.

In drier climates I was able to run all day long if I had too in 100+ F. In humidity 7 miles can be tough in the 80ies. It's so much harder in humidity. So don't beat yourself up for not so good performances.

also a virginia runner wrote:

It's been MISERABLE for running in VA since the cool streak ended. I'm probably averaging 20-40 seconds slower per miles on my runs ever since the heat and humidity hit. The other day my shins were sweating after like 20 minutes. It'll get a little better once you've adjusted a bit, but it won't be the same as running in March/April. The good news is that it's all about effort, and when fall hits you'll feel great - slower speeds now doesn't mean you're just slow and will have to "start over" with training in the fall. Make sure you hydrate, and bring water with you on your runs even if you normally wouldn't (I don't bring water for anything shorter than 14-15 miles in the winter, but in the summer I'll bring water if I'm doing more than 6 or 7).

Also in Virginia and it has been tough..I'm really happy I set my mind on a HM TT next Friday....

Thanks for the replies everyone. Gonna take a look at my training and diet to see if that could be affecting my running negatively, and if not I'll chalk it up to the weather and know that I'll be that much faster in the fall.

dew en pointe wrote:

NeedForSpeed wrote:

use this to calculate dew point

This just proves that the OP MAJORLY exaggerated the heat and humidity he runs in.

Yeah, according to OP, the dew point is 82 degrees everyday which is highly unlikely. It hit 81 today in SW Florida which is the highest so far this summer. Dew points anywhere from mid 70s on up will markedly affect how you fare, esp. on harder/longer runs. Acclimatization will only get you so far. Slow down, run by effort, ditch the watch until Sept, get a 2nd or 3rd pair of shoes so they'll have a chance to dry out between slogs, get a seat cover for your car if you're driving to runs, try to stay on shady routes, ....

I'm curious, how do these paces compare to your 5k or 10k race paces? Is it possible you could slow down on these runs while you acclimate to the heat? 70 degrees and 100% humidity (what it's been lately near me at 6am) does not feel good, but you should still be able to come close to typical easy paces, if not your regular lactate threshold or faster paces.