Temperature-Based Watering Schedule

I have a suggestion.

I used to think that midday watering on a very hot and sunny day was bad for the lawn, but I recently learned that was a myth. I’ve been reading and it is actually beneficial to do some light midday watering on hot days to cool off the the soil and reduce the effects of heat stress in the lawn.

I’m going to keep my primary watering early in the morning, but it would be nice to have a second midday schedule that starts only if the temperature is above 85 degrees, and runs for just a few minutes. I can set a schedule to do this everyday, but on cooler days, it would be a waste of water.

The simpler way of accomplishing this would be adding a “Only water if the temperature is above X degrees” feature to a specific water schedule.

But heat stress comes into play when multiple hot days in a row strike with no cooler recovery period. A smarter way of implementing this would be “Only water if the temperature average for the past 3 days is above X degrees.” Thanks!


Thanks @Ed3120. Could you point me to where you’re getting this info? I’d love to check it out.

I’m also interested in the info. you refer to. It seems that you can use IFTTT to do what you’re asking. I haven’t used the one for the Grass but created it to give you an idea. It fires a watering that you define in minutes whenever the temperature hits a specific value. The other one should enable a fixed watering schedule that I have only when temps rise above 110F.

I will follow this also to see the original article. I’ve always been lead to believe that too much watering is not healthy for your lawn. In my opinion, the grass canopy should be providing enough shade for the soil until your next watering… which if you are hitting 100+ degrees on a daily basis, I would hope that your grass is being watered at most every 3 days or so. Now if you have patches on your lawn where the grass cannot provide a natual shade, then I guess that’s a different story.

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Generally speaking, watering in the middle of the day won’t harm plants, however it is usually discouraged due to the higher evaporation rate of water being applied to the plants.

The people on this forum reside in many different areas, types of climates and even within their own property, microclimates. There are so many variables, there is no “one size fits all”.

I don’t water during the middle of the day here in the Sonoran desert due to the high evaporation rate. Best practices dictate that a more efficient time to water is in the wee hours to avoid the hottest time of day. Since the night time temperature can at times, still be in the high 90s, best practices indicate I should water when it’s cooler–like the chilly 83 degrees we experienced at 6 a.m. this morning. In other climates, it may be OK to water at night.

@Ed3120 is in New Jersey and the Cooperative Research & Extension service at Rutgers provides this publication: Best Management Practice For Watering Lawns


“Time of Day
The most efficient time of day to water is late evening
through early morning (between 10 p.m. and 8 a.m.). It is
generally less windy, cooler, and more humid at this time,
resulting in less evaporation and a more efficient appli-
cation of water. Water pressure is usually better at night
resulting in a more uniform application of water through
sprinklers. Contrary to popular belief, watering at night
does not stimulate disease development.”

Rutgers Cooperative Research & Extension
N.J. Agricultural Experiment Station
Rutgers, The State University Of New Jersey
New Brunswick


It’s called syringing and you can induce wet wilt as well as increase soil temperatures http://gsrpdf.lib.msu.edu/ticpdf.py?file=/2000s/2006/060307.pdf

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I would not water for more than 3-4 minutes assuming you are around 1 inch per hour

Interesting article @plainsane. I’ve not been that interested in turfgrasses, but following this forum reminds me of how much time and effort my father put into our front yard. He enjoyed it when the neighbors complimented him on how beautiful our lawn was.

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I don’t think this IFTTT fully allows replacing awater schedule, as IFTT does not allow to set a specific time when to water.

I also would like an option to set a schedule to only water if temperature above a certain value. So this would be similar to the freeze schedule, but instead of below the tempare it’s above.

E.g Only water if temperature above 20 degrees, better would even be an option that the “high” tempaérature could be chosen: E.g only water if High temperature of the days is 20degrees or higher.

This cannot be achieved with IFTTT alone, as specific time needs to be chosen too. IFTTT only allow to water the moment the temperature passes which could be any part of the day, this is not wanted, I want it at a specific time of the day (where noone is in the garden). THanks

Hi Sunny, I’d say that this theory is in the experimental phase at best. Most standard sprinkler heads installed may not have misting capabilities ( I.e.,unless each head is tweaked or changed out). Then you have the humidity factor. On high sunny, high humidity/ high heat days, the misted water will sit on the leaves and heat up. Water is an excellent conductor of heat. Excessive heating conditions will develop since the water has no place to go. This will damage the grass.

Nevertheless, If the method is proved out and used, it would not be a daily type of scheduled event. It would require pretty advanced scheduling and would have to take many factors into account including regional conditions, wind speed/direction, humidity, soil type, grass type, etc. Considering these factors, I re commend and prefer the safer, Rutgers method.

Sadly enough this behavior is only viable to gold courses where fans can be easily stood up to evaporate moisture.

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