My geographic location is bitterly cold right now, and making me long for autumn weather.
Are there any places in the world with year round temperatures that hover between 40 and 70 Fahrenheit?
San Francisco. That’s an average, it does get into the 80s often in summer.
England:
Addis Ababa, Ethiopia. I arrived there prepared for tropical weather, but most of the year, it’s in the low 70s day and the 40s overnight. I had to borrow warm clothes until I could buy some. For some reason, when I travel, it never occurs to me to check out the climate before I go.
Maybe closer to your target would be Bogota, Colombia, with every month’s average hi-lo near 68 and 48.
If you want perpetual autumn, Britain is for you. I find the weather here very boring - give me a proper continental climate with baking summers and freezing winters any day.
Admittedly here in southern England it might still be a bit extreme for you: most summers have a few days in the high 80s or occasionally low 90s. It’s rare to have daytime highs below 40F even in winter, although it gets down to maybe 20F overnight a few nights a year.
For real lack of extremes you probably want a coastal location in northwest England, or Ireland. Cold winter weather and hot summer weather are both moderated by the Atlantic. Bring an umbrella, though.
“The coldest winter I’ve ever spent was summer in San Francisco” – Mark Twain
Try The Isle of Man, with an annual monthly max of 12.8C (55F) and a min of 7.6C (45.7F). They do get quite a lot of rain though.
The Silicon Valley in California has pretty consistently mild weather.
Redwood City’s city slogan is “Climate Best by Government Test”
The Canary Islands and northern Mediterranean coast of Africa were runners up.
Plenty of places in mountains in the tropics will answer the requirements of the OP.
I prefer places that get a bit warmer during the day, likeCerro Punta Panama, where the temperature is 86-93 F during the day and 72-73 F at night. Higher elevations above the town will be cooler.
According to my wife, Huanuco, Peru is “Land of Eternal Spring” staying on average between 50-80F.
Of course, that’s an average and today’s high is 90F just to prove me wrong.
Another vote for Bogota. I’ve been in both December and July. Not much difference in the temperatures either time.
Actually if you’re looking for year round consistency Colombia is a great choice.
Bogota, elevation 8,600 ft, autumn year round, 40F low, 70F high all year round.
Medellin, elevation 4,900 ft, spring year round, 60F low, 80F high all year
Cartagena, elevation 7 ft, summer year round, 70 F to +90F all year.
Year round winter is tough to find there though (except for a couple of mountain tops).
Southern California near the beach is close. It’ll be into the 70s. If you want 70 as the absolute max, the whole west coast of the US from about halfway between LA & San Fran all the way up to the Canadian border will do it.
Or inland partway up on the first mountain range.
This is called the fog belt for a good reason … it’s always foggy in summer … no one mentioned wind yet but the North Coast does get to 60-70 mph with gusts over 100 mph every few winters … and we measure rainfall in feet, not inches …