As a Canadian, I know all about dressing for extreme cold, but dressing for a heat wave like we experienced here in Alberta recently is much more challenging for me. If I lived where these temperatures were the norm, I’m sure I’d have a wardrobe full of cotton and linen, but alas, I do not.
Day after day, I wore shorts and sleeveless tops on repeat. Thankfully, I have plenty of both and was able to mix and match to create numerous different looks from casual to dressy.
Of course, there are those who say that women my age shouldn’t wear shorts, but you probably know by now that I don’t follow fashion rules, particularly those related to age. When I was younger, I was self-conscious about my skinny legs and knobby knees, but not any more. I actually don’t think they look too bad for 70!
Most summers, I wear shorts mainly for golfing which is why I have several pairs. I prefer them to hit just above the knee and to be loose enough to move comfortably. For a dressier look, I wear those, like this black pair, that are slightly more tailored looking.
In addition to shorts and sleeveless tops, I’ve been living in sandals. Again, I have several pairs. My new Ecco walking sandals have been getting plenty of use as have my golfing sandals. In addition to those, I have dressier as well as casual pairs to choose from.
Perhaps the most important thing that I wear during a heat wave though is sunscreen. Before I leave the house to play golf, go for a walk, or work in the yard, I slather on a good layer of a broad spectrum SPF 50+ lotion to protect my delicate skin from the sun’s damaging rays.
It doesn’t look like I’ll need to do that as often for the next few days though. As soon as I started working on this post, the weather changed! It’s much cooler now and we finally got some of the rain that we’ve been needing so very badly!
Following Augustine 
I think you can wear sleeveless tops very well. Most of us over 70 do not have great looking arms!
JanF
I was also self-conscious about showing off my skinny arms when I was younger, but after working out with weights for many years I got over that and now I’m very comfortable wearing sleeveless tops.
In deed, it is easier to dress for the dry cold of Alberta than the heat. High relative humidity combined with high temperatures limit the evaporation of sweat. The sweat builds a thin film on your skin which hinders heat release. Furthermore, some sweat drops off thereby reducing the amount of sweat that can contribute to evaporative cooling. Best fabrics for heatwaves are moisture wicking. The fabric takes up the sweat and so the area for evaporation increases. Try wearing sports clothes designed for high activity. They are typically moisture wicking or have special knitting techniques or fiber combination that help evaporation.
Thankfully, it tends to be quite dry here even when it’s hot which is definitely easier to tolerate than high humidity.
Forgot to say that I think the length of the shorter black shorts looks more youthful and suits you!
I do think that they look dressier. Perhaps that’s partly due to the length.
I envy your long slim legs wear your shorts while you can.In New Zealand our summers are very humid so I find dresses much cooler than shorts.
I was wishing that I had some casual summer dresses to wear during this heat wave.