Technically I suppose you want longer days. The amount of solar irradiation is very much lower the further from the equator that you go and hence lower temperatures.

Aberdeen has 4.52 in May, 0.32 in December - North of Moscow
London has 4.59, 0.6 in May and December respectively - well north of Winnipeg
Des Moines has 5.39, 1.64 - Similar latitude to Rome

Measured in kWh/m2/day onto a horizontal surface

Interesting that despite being very north the longer Aberdeen days in Scotland almost make up for the lower height of the sun in the sky.

Of course the surrounding ocean very much modifies the temperature so it seldom gets really hot in Atlantic Europe.

Source: Solar Irradiance Calculator - Useful Sun power tool