Yes this is the time of year when you hardly know what to do with yourself, let alone finding appropriate things (activities) and more to do with your ASD kids.  The weather is typically's either raining, windy, cold, or all of the above.  And just when you've gone grocery shopping for ingredients to your best "comfort cold weather" foods, the sun comes out and there it is, a day that pushes the 70 degree mark! 
The weather is totally Bipolar.  It can't make up it's mind.  And as parents of kids with Autism, it's hard enough to create a plan of things to do with our children that will keep everyone happy- including the neurotypical siblings! 
So what to do? 
First- try to see the silver lining.  The fact that it's February, means that Spring is just a few weeks away!  We have Valentines Day to celebrate and there are even a few school holidays that we can look to for extra "off" time to find fun things to do with our kids that will tide us all over till Spring comes in. 
Below -find a list of ideas of places to go (indoor and outdoor) to accomodate the weather.
In order to survive, we need to make sure we have both indoor and outdoor activities planned for our kiddos.  On the weekends, it's much easier in any other month to plan ahead.  You either pack everyone up in coats, hats, gloves, and boots, and bring your backpack filled with cold weather treats and video games.... Or in the Spring and Summer months, you simply let everyone slide their sandals on themselves, and you know that you hardly need to bring anything for anyone.  Maybe pack up a few sweatshirts and some H2O to go, and you can be on your way anywhere.
So- look to your own community for indoor 'things to do' for kids.  If you have indoor play areas, or indoor museums specifically designed to keep kids minds busy, put them on your "outings list".  Still, you never know when a warm, sunny day is going to pop in and say "hello" and you want to be prepared, because every single one of you need the warm sun on your skin by now, for the Vitamin D if nothing else.  For days that happily come in like these, make sure you know where the latest and most fun outdoor parks are.  Bring along your kids' bats/balls, & other outdoor game items they can kick around a wide open dry field.  It's unlikely that anything is going to be grassy or wet with dew yet, so you don't have to worry about those things.  Still- be ready for activities in both worlds.
The best advice is to make a "double column" list of places to take your kiddos for fun.  And then go on one of the big search engines "Maps" sites, and go the the "Directions" section.  Type in your address, and then one by one, type in the various locations of all of the fun places to go- Print Directions to each one. I like to staple them together so that I'll have them all together in a one place and can easily go to my lists when I need them. 
-  Laser Tag (indoor) very fun for everyone boys and girls
-  Roller Skating/Roller Blading (indoor) bring earplugs for your ASD kids- they are loud
-  Ice Skating Rinks (indoor) boys can use the Hockey Skates to feel more like they fit in
-  The Movies (indoor) Obviously- this one can be good to have earplugs for as well
-  The Mall (indoor) great because everyone needs to update their wardrobes
-  Close Park (outdoor) Great for sports- dry open fields that have been unused
-  Basketball Court (outdoor) Great for basketball and other fun games too-
-  Museum (indoor) typically inexpensive & they have ones with children's sections
-  Aquarium (indoor) if you're lucky enough to live near one they are great all year long
-  Gymnasium (indoor) Gyms typically have "open Gym" time to the public
-  Classes (outdoor and indoor) Weekend classes tend to start up in the new year
-  Open Hiking (outdoor) A great way to get your kids back in motion slowly & see beautiful things!  Bring jackets and a camera and be ready to see animals, as they are out this time of year.

At Home Activities:)
When everyone is stuck at home, especially when the weather is crummy for a while, it's great to have some things for everyone to do.
- ART- buy some new (cheap) art supplies and a book about how to draw/paint
- Cooking for Fun- this can be especially fun for kids with special diets- find a new meal that they haven't ever been able to have, and find a new way of using new ingredients to get your kids into helping you cook it!  So fun and a great benefit- the outcome involves a meal or dessert!
-  Get Movies-  From Netflix, to online movies, to Bluerae to DVD old school...watching a movie as a family can be the most fun thing you'll do all weekend.  In our home we take turns letting each family member choose the movie, keeping everyone happy. 
- Finally- Integrate these 3 Together for a Fabulous Weekend Day Indoors on a  Cold February Day!  Especially around Valentines Day!
Make Valentines as your Art Project, create a Valentine specific meal- in the shape of a heart, or something sweet, drizzled with Vegan Chocolate, and then top off your day with a family movie by a warm fire, and everyone will go to bed Happy!!!   ENJOY!