A lot of it will depend on how well your soil retains moisture, if it is mulched or not etc... 86 degrees is really nothing to fret about though. If they are newly transplanted, you will want to check the soil moisture cloe to the roots daily to make sure it is not drying out. Cucumbers tend to be fairly shallow rooted so may need to be watered more often. When temps are in the mid 80's here, I can usually go at least a few days between watering, but it all depends on how quickly the plants are growing and how moisture retentive your soils are. Sorry there is probably not an exact answer for you, I don't really start daily watering until temps are running mid to high 90's or pushing triple digits.

Just check the soil daily until you get a handle on it.

I read on a website to keep checking if the top soil is dry. If it is, then give it water until a puddle starts to form, meaning the soil is saturated to the point where it won't hold more.

I read on a website to keep checking if the top soil is dry.

That is just the opposite of the normal advice. Disregard the surface dryness since it isn't relevant or even an indicator of how much moisture is in the root level soil where it counts. Plus if your soil is heavily mulched as it should be you can't see the surface soil anyway.

There is no set watering frequency for any plants. There are too many variables that affect it to set any schedule. Different crops need different amounts of water, different soils retain or drain at different rates, weather, method of applying the water, air and soil temps, in ground or in containers are just a few of the variables.

So you learn to water when the plant needs it, not by the day of the week or the time of day or the number of days since rain or when you last watered, etc.

Pull up the many other discussions here on how to water for all sorts of tips and techniques for determining when plants need to be watered.

I use the finger int he soil method. Basically you just shove your finger into the soil about 2-3 inches and feel if it's still moist. Do it in a couple of different places. After a couple of weeks you'll start to get better at knowing when you need to water and when you don't.

Also, I don't know if pumpkins are any different, but generally it's better to give (outdoor) plants a really good soaking every few days rather than a light watering every day or every other day. This is especially important if you live in an area that gets pretty hot.