Dry season is a mid-game challenge that appear from day 60 till day 90, after which the season will switch with Wet season back and forth every 30 days or so. You will have massive difficulty trying to not die due to underpreparedness.

During dry seasons, rain may not even come at all for the entire months and can force unprepared players to spend all day just trying to not get dehydrated and die anyway from coconut induced diarrhea

Just a reminder that you should already memorized this by now

• Keep halves to collect rainwater anytime, for early game you'd want to go back as soon as it rains to collect water. You can also gather rainwater straight from shelter and caves
  
• You can drink coconut, but keep it no more than least twice a day and don't eat the flesh. Coconut saturation also causes diarrhea which make you thirst even faster
  
• Fruit recover some thirst, especially mango (found on jungle highland). Fish and other seafood can also recover some thirst when eaten raw, just watch out for parasites
  
• Always unlock both wetland puddle before the week end, you'll need those to collect mud for later
  
• Do not chop down any cleared banana trees. Trust me, it'll be an important source of emergency water later
  
• Most importantly, don't forget to take care for your other bodily need. The deadline is very long and you don't have to prioritize on this for way too much, but it's better to always be able to work at your most efficient state.

Obviously, you don't have to dedicate everything on preparing for the dry season, there is enough time for everything.
Mud will be the main component to building most of these, it can be found by exploring the mangrove forest or by digging up the puddles by the wetland. Second component is Tempers, easiest one would be sand, dug from the bay/beach. Alternatively you can use ash, crushed conch, plant fiber, and rice stalks. Combine both the mud and temper material to make a mud brick which will be the main component you need to start building the Kiln
For now, make sure you have plenty of vases. Farm conservatively, exception maybe on plants that grows very fast and maybe the rice field which only need to be watered once. Glazed vase can store water indefinitely, making it requires salt which you can easily make by boiling seawater

Now consider filling for this checklist

• A Kiln, build it asap, as soon as you have found a place you want to stay on. Do not make permanent shelter on area with seawater access, you'll find out why very soon.
  
• A mud stove (not necessary to this guide but essential for your quality of life)
  
• 3-4 clay vases
  
• At least 1 reservoir built
  
• Couple of Glazed Vase/ Cooking pot/ or a Jerrycan

If you already completed this prior to day 30. I'd suggest spending the rest of the time to build a more proper shelter like a mud hut. Start investing early by planting several banana and mango trees. Feel free to focus on other aspects too.

Now, water at this moment will be plentiful. Day 30 to 60 will also comes with storm. Watch out for hypothermia, otherwise it's actually much more easier to deal with if you have at least a shirt and pants. Storm will also cause you to waste time while exploring shores, only visit such location when it's not storming.
The well requires mortar to be built which requires quicklime, you can get plenty of quicklimes by baking large rocks on the kiln. Plenty of small rocks can be easily found on the Desolate beach and Eastern Highland's blocked tunnel.

Now, the deadlines. You'll have a very hard time on day 60 if you fail any of these

• Finish a second reservoir, specifically important on farmer class since Granpa also need to drink water
  
• Explore the wetland further and then bring a torch/candle to explore the dark cave, this allow access to small but replenishable water puddle
  
• Build a well on the wetlands (You might not have enough time to finish a reservoir so this will be your second best bet).
  
• (Optional) Craft an Alembics, made after the clay pot cooler. The alembics can desalinate seawater into drinkable one
  
• (Optional) Start preparing the cistern on your main base if you have the extra time. It won't be of effective use by the time you finishes it, but you can move water from reservoirs to the cistern prevent evaporation
  
• (Very Optional) Explore the cavern network until you reach the damp cave. There contain a much larger source of freshwater which can be directly linked to the dark cave from marshes.

This is where new player will scramble trying to not die. Having no source of water will make you scramble trying to preserve yourself, only to screw big time because you also need to care for your hunger and potential injuries. There may be a rain (once) during this season, but there may also be chance that the rain may come way too late.

Practice water conservation by following these tips

• Use only saltwater on the coolers. Wash yourself on the seas, bring a vase full of it if you could.
  
• Give Grandpa and macaque friend coconut water whenever possible
  
• Don't start any farms at this moment, seriously
  
• Occasionally empty the water from the wetland to refill your reservoirs. The well will recover itself and the puddle are only going to dry out on their own eventually
  
• With 2 reservoir, once the other hits below 50%, move the water to another to minimize evaporation
  
• Don't use your emergency water from enclosed containers until you are sure that there is no more sources or you need the containers for something else
  
• Avoid food that require lots of water to prepare like Yams, Sago Flour, certain Dishes
  
• Avoid catching fever from bug bites, these disease causes dehydration

Adapt and Persevere, hope this short guide helps you or even teach you something new.

Did you fail to complete any of the deadline? Or was it because by the time you found this guide, it was too late. Well, here is some of the way you can still not die of thirst as you wait for rain to come back somehow.

• Stock up as many coconut as you can, only drink twice a day and do not eat the meat. Keep exploring the beach
  
• Start cutting down banana trees as soon as you're really running out of fresh water. Put a bowl in it and the bowl will eventually fill up
  
• Boil the raw water whenever you can, You are already trying hard to survive, no need to punish yourself even harder with cholera
  
• Bring salt water back to your house to refill cooler, wash, as washing occasionally with
  
• At least complete building the Well on wetland if you haven't
  
• Build an Alembics after you finished the well, the progression goes as Kiln > Vase > Reservoir > Cooler > Alembics. This item are able to turn salt water into something drinkable