The Mediterranean and California coast have a moderate climate without extreme temperatures, 10-20C 55-70F year round.
Cities like Bogota, located in the mountains close to the equator, are sometimes referred as “city of eternal spring”, with cooler 5-20C 45-65F year round.
Are there cities or areas that have stable winter-like weather year round? Somewhere around -5-10C 30-40F? Most Nordic cities seem to have seasonal climate.
My best guess would be cities in the high mountains (like the himalaya), or in the polar circles. They would still have summer and winter, but it would be more like, winter and more winter