Below is a brief outline of what to expect on the Camino de Santiago for each month of the year.
Camino de Santiago in JanuaryVery cold and wet in some parts of the Camino and not many people to travel with you.
Camino de Santiago in FebruaryStill very cold in many places, though not as bad as January. Some travelers.
Camino de Santiago in MarchWeather is cool but not unpleasant. More travelers now on the route. A very good time to walk.
Camino de Santiago in AprilWeather can be be quite warm in some places now. More and more travelers on the route.
Camino de Santiago in MayCould be very hot in May, though weather varies more on northern Spain than it does in other parts of the country. Route is getting quite busy now. Some hostels may be full by the time you get to them.
Camino de Santiago in JuneHot weather can be expected. There is reportedly a slight dip in 'traffic' in June compared to May, though still more than in April.
Camino de Santiago in JulyVery hot and lots of other travelers. Can you cope with the sweaty people who haven't showered for days (because the line for the shower was too long)?
July 25 is St James's Day, a popular day for Catholics to finish the Camino. In Jacobean Years, expect vast numbers of people walking in July.