Is March spring season? I don’t want to come in high summer, but I’d still like to be able to travel outside Reykjavík. Is the weather nice in March/April? Are the ice caves still on then? I’d like to go to Jokulsarlon glacier lagoon and maybe to Akureyri up north. Can I go camping in those months?
I’d say March is still winter, but April is the beginning of spring. The south part of Iceland gets warmer earlier in the year than the north part, so in April there shouldn’t be any snow in south Iceland except some small patches at mountaintops, whereas there can still be quite a lot of snow in the Westfjords or in Akureyri and Siglufjörður.
The weather is so unpredictable all year round that you can’t accurately say if it’s going to be nice or not. Now it’s February, and normally there’s some snow and frost in Reykjavík but it feels like spring, with just rain and 10°C! You should prepare for all kinds of weather, it may snow one day, rain the next and then be sunny and nice on the third.
What is definite is that the daylight is already lasting for quite a long time in late March and in April. On the 21st of March is equinox, when there are already more than 12 hours between the sun rising and setting, and after that the days become longer than the night every single day until June.
The ice caves are open depending on the cold weather, so normally they are only open until the end of March (if it’s cold enough) but are definitely no longer open in April. There are still man-made ice caves in Langjökull glacier that you can go to all year round - and you can also go glacier hiking all year round and see a bit of blue ice
Going to both Akureyri and Jökulsárlón should not be a problem in either March or April, unless there is a storm and some road closures. That could happen at this time of year, normally just for a day or so, so just make sure you check the weather forecast before you drive anywhere.
It is too cold to go camping in March and April, and campsites do not open until May. For budget accommodation check hostels, there are nice hostels all around Iceland, my favourite one is Berunes hostel in east Iceland
There is actually another Ice Cave open in April it’s in Katla and its set up in the mountains so it doesn’t melt and break apart at the same time as the main, crystal ice cave. I’ve heard there are some differences, it’s a bit more expensive and somewhat darker than the crystal ice cave and doesn’t have the same blue color… but hey it might be worth it checking it out to see an Ice cave in Iceland if you have missed the Crystal Ice Cave. The Katla Ice cave is open throughout April all the way until start of May! It’s crazy! You can also do snowmobiling even though its not winter… and glacier hiking as well!
Hope this helped somewhat