Under some special conditions, can heatwaves make places like 70 degrees latitude north hot in the summer (like 32 C or 90F)?
Yes; under some special conditions ... places like 70 degrees latitude north can get hot in the summer; however ... heatwaves are somewhat unlikely. The special circumstances would most likely occur during mid-summer when the solar angle of incidence is greatest and a strong southerly wind brings warmer temperatures into high latitudes. Heatwaves are defined generally as daily maximum air temperature more than 10°F above normal for at least three days. This threshold may be more difficult to achieve.