The actual fallas (la cremà - when they are burned) is only on the 19th March (into the early hours of the morning of the 20th) - St Joseph’s day.
when you say you are going for “a couple of days” - is that date included?
Only went to the fallas once, decades ago, and had such a great time that I don’t really remember it. What I am extremely familiar with is the Hogueras/Fogueres in Alicante which climaxes on June 24th (St John) and involves better weather. They’re not that different.
Mascletas are huge explosion rallies (think of a sonic domino track with flourishes and surprises). There are rather more limits on decibels than there used to be, but there is usually a short intense burst where they can blast the guidelines. To fully appreciate a mascleta you need to be close so that it ripples through your abdomen, rattles your jaws and slams your skull. When the choreography works it is a furious emotional assault that leaves you elated. Not all mascletas are equal, quite a few are lacklustre. But when you’re present for a masterpiece it really is something else - it’s an Art form that can only be appreciated live. If a standout example happens but you’re standing too far away from it, you won’t even realise what it was you missed out on. Position is key, which is why you’ll see concentrated crowds - join them!
As for the fallas themselves - well, they’re not paper, goodness knows what plastics are used nowadays. If you haven’t got asthma or respiratory issues, great!
Don’t wear anything fancy, if you don’t want to show your countours or nipples dress accordingly, if you go out this night you are likely to get wet. The fallas give off intense heat and the bomberos (firefighters) will protect/relieve you with their hoses. There are only so many fallas that the fire department can attend to at a time, so once one has finished, join a group of local youths and go running to the next one. Often it’s the smaller, less celebrated fallas that are most fun. A few of the bigger/most lauded fallas get featured in the main timetable. Oh yes, wear running shoes that will survive water and ash. Your phone and money needs to be water tight and (along with keys) pickpocket proof.
Be patient. Timetable or not, there is no fire until the bomberos say so - they are the gods of the night. Enjoy the anticipation, have a drink, chat to people.
There are also parades - you’ll see millions lavished on dresses, hair couture and flowers. The cost of each dress is the equivalent of buying a motorbike, or a small car. Compliments for those walking to and from the processions in regional costumes will be much appreciated (the word you want is “¡Guapa!”)
There will be more going on than shown here, but this is a basic program (“Offering” means procession and lots of closed roads and routes - not a great time to get a taxi!)
https://www.visitvalencia.com/en/eve...s-program-2020
Have fun!