We are planning a trip to Spain beginning mid-September into early October 2019. We want to spend at least half the trip in southern Spain, including some hiking and birding. However, we are becoming concerned that with the heat wave and wildfires the area will be parched and possibly smoky then. I realize the current fires are in the northeastern part of the country, and I also realize that no one can predict the weather. However, I have read that the hill towns region is generally very dry by early fall. I'd appreciate feedback from others who have traveled this itinerary in early fall in recent years. Should we consider waiting a bit later, beginning the second week in October?
In general, if you plan to do hiking in Andalucia I would definitely wait until October if you can. Mid September may potentially still be around the lower 30s C (90s F) in many places. You will have more certainty of temperate/comfortable weather in October.
Edit: I know little of birding my post is just taking into consideration the weather.
I am also a birder. I was in Andalusia late October into November 2017. Prior to that, it had been hot and drought. Also fires in Parque Nacional de Donana. I had a bird guide booked for Nov 1 and we didn't go into the park to the marshes - as they were all dried up. We visited the east side of the Guadalquivir River as there are extensive rice fields that were flooded and migrating flocks were there instead. Later we did go into Donana to picnic areas for forest birds. But boy, you could tell birds were programmed to avoid humans (given that they still eat passerines), so most birding was by ear - which I can't do in a foreign country and it was hard work to see 5 species in an hour. I had success around Alhambra and the creek that runs through Granada a few days prior, and the parks in Seville would be nice.
Check out wunderground website for historical weather for the past 5 years for your cities of interest. It gives temps and precipitation.
If you are in Seville and want a guide, I used Ecotono Birding. Blanca was my guide though I had dealt with Rafa prior. Not sure if you are used to birding Europe, but it seems everything is 'common #####'. So different than in North America.
I realize my time was later than your consideration, but you can at least get some idea. As you mentioned, everything was parched as even in November, the rains had not started to 'rain on the plain'.
If you want a few more birding details, send me a PM.
All the British birding companies I have just checked out run their Spanish autumn migration holidays between 5 and 28 September, trying to time the stork and raptor passage southwards.
Do you want to see the migration or just do some general birding? October will be ok for general birding, but go in September for the migration.
I have been in April and May for the raptor spring migration in the Parque Nacional de Monfrague and general birding in Doñana.
I am not fully up to date with what migrates when over Spain, but we had a 50 species list for the rice fields area. Flamingo, grebes, waders (500 pied avocet), turns gulls, masses of white stork, some black stork, egrets, 1 spoonbill. Glossy Ibis are not year around. Booted eagle, many common buzzard, and marsh Harrier. various chiffchaf and cisticola.
Of course, I didn't have a variable time to travel, so I had to be happy with what we could find - I was not disappointed.
You could just send an inquiry to one of the local bird guide companies for advise whether one time frame is better than the other...no commitments required :-)
We have had perfect, very comfortable weather in late October, early November on two different
trips to Andalusia.