Please reference links below to view historical weather averages at each of the main stops on your pilgrimage.
Note: The most popular time to travel to Portugal, Spain & France are during the "pilgrimage season" in the spring and fall while avoiding the hot summer months. This makes April, May, September & October the best months to travel. This way you can enjoy good weather and all the festivities this season has to offer.
Lisbon
https://www.timeanddate.com/weather/portugal/lisbon/climate
Fatima
https://www.timeanddate.com/weather/@2268326/climate
Salamanca
https://www.timeanddate.com/weather/spain/salamanca/climate
Burgos
https://www.timeanddate.com/weather/@3127461/climate
Lourdes