Our diverse climate is ideal for cycling it just depends when and/or where you want to go cycling!
We recommend that you do bring some rain gear; however, equally we recommend you bring suntan lotion and a sun hat!
Weather is not easy to predict especially when adding the fact Portugal and Spain make a vast and diverse territory.

We have coastal areas and low altitudes vs. inland areas with medium altitudes and mountain areas.
NW and Northern Iberia have an Atlantic climate, SW and Southern Iberia is mostly Mediterranean, Central Iberia has definitely a Continental climate.

Lower altitudes and Mediterranean climates are usually mild and great destinations for biking throughout the year,
these include e.g. Lisbon area, the Alentejo or the Algarve in Portugal and Andalucia or Valencia in Spain,
being particularly nice in the Spring and Autumn, especially on the coastal areas.
Summer is warm, sunny and quite dry, with very low humidity, especially in Portugal.

Medium altitudes and Continental climates have very high temperature amplitudes,
Winter (late November to early February) is colder and sometimes rainy,
Summers are short (July and August) warmer but dry (with low humidity).

From early March through November all Portugal and most areas in Spain are, no doubt!, pleasant cycling destinations.