Ventilation in a hot & humid climate

Yesterday a reader from Florida asked for specific instructions on how to keep a hive well ventilated in a hot and humid climate. This is a good question. Although colonies can usually survive hot and humid conditions, they will produce more honey and be less stressed if they don’t have to spend all their energy cooling the hive. Here are some suggestions:

  • Keep the hive up off the ground. By placing the hive on a stand, you allow air to circulate on all sides—including the bottom.
  • Use a screened bottom board without the Varroa tray. A screened bottom allows air to circulate into the hive from underneath, and it has a much larger surface area than a standard entrance.
  • Use an upper entrance. An upper entrance, either drilled in the top hive body or cut into an inner cover, allows the hive to behave much like a chimney. Air will come into the hive from the bottom entrance or screened bottom and exit through the upper entrance.
  • Even better than an upper entrance is a ventilated inner cover. A ventilated inner cover is screened in the center and has end pieces that are higher than the side pieces. These end pieces hold the telescoping cover aloft so air can circulate through the sides. The screening should be small enough to keep out robbing bees. (see photo below)
  • Keep your hive in the shade. Left to their own devices, bees will usually select shaded areas in which to live. A little morning sun is fine, but a shady location will allow the bees to spend their afternoons foraging instead of fanning.
  • Hives in hot locations should be painted light colors and have a white or metallic roof.
  • Place a slatted rack under the bottom brood box. Slatted racks can aid ventilation by reducing congestion below the brood nest and providing more space for air movement.
  • Do not allow your hive to become too crowded. If the bees need more space give them an extra brood box.
  • Make sure your bees have a source of clean drinking water.


Ventilated inner cover--end pieces are shimmed to provide maximum air movement.


  • “Do not allow your hive to become too crowded. If the bees need more space give them an extra brood box.”

    I use all 8 frame mediums. When you say give them an extra brood box, is that meaning to insert it down low? With all mediums, 4 boxes are my basic hive. I wouldn’t want to put the box on the very top, but does it matter where else I would put it?

    Thanks. Love your website!

    • You should put a new brood box either on the top or the bottom of the stack–just don’t put it in the middle.

  • SHB [small hive beetles] need 45% humidity or better in order for their eggs and larvae to mature. Anything under that and they can’t reproduce, anything at or over and WATCH OUT!!! Ventilation for our colonies is vital to helping our unnaturally kept bees in painted wood boxes that can’t respire. Remember, unpainted wood can and will wick a certain amount of moisture to the outside. Swarms living in house walls can stay there for years because, in most cases, the walls leak air like a sieve and the drywall and siding wick moisture. Bees kept in our hive boxes must be allowed ventilation, MUST!!!

  • Hi, Rusty,

    Was wondering if you could explain how you made these screened inner covers . . . specifically, what dimension wood did you use, and did you use something on the bottom of the cover as a spacer to preserve bee space? Was thinking I could use the spare Imirie shims I have, staple the hardware cloth to the bottom, then cover the edges with some flat trim . . .


    • Joel,

      Someone else asked me this and I never got around to posting my instructions. I’ll try to get it up this week. The biggest problem is supporting the lid above the screen so you get air flow, but there’s an easy way to do this. You could also alter your Imirie shims, if you want. I’ll give you a head’s up when I post. Thanks. Good question.

  • Carol,
    I would think fiberglass screening would be ok, although it degrades with UV exposure. Aluminum screen would be better, if not hardware cloth. In the 1980’s I bought some cheap stormdoors with, I guess, plastic screen that the grasshoppers loved.

  • Has anyone tried using a terra cotta clay rectangular flower pot to do a top bar hive in a hot humid climate? It is breathable and stays cool inside. I am thinking of trying it.

    • Tyania,

      I saw this done at Oregon State University using a regular round pot. They put wooden slats over the top of the pot and a hole near the bottom. Bees seems to love it. I have a photo somewhere.

  • Hi Rusty. I stumbled upon your website a month or so back after getting my first couple of hives and have been reading the blog posts almost continuously and really enjoy the more natural but realistic approaches you advocate. I live in Beaverton, Oregon and graduated from Oregon State and got interested in beekeeping after taking a class in entomology in the summer from the head beekeeper at OSU at the time. So I was reading this post and really want to increase the airflow in my larger colony I have which is two deeps and a medium they are just starting on. I currently have Vivaldi board but with this hot summer we are having I’m thinking of building one of these screened top covers but I’m wondering would it be better and with the picture you posted, it looks like the cover would allow rain to come in through the side and get into the hive? Obviously I wouldn’t use this during true fall and winter but there is sometimes the brief errant rain storm burst and I’m wondering if this is an issue?

    • Wei,

      My telescoping covers come down over the sides of the screened inner covers. There is a space between the telescoping cover and the inner cover that allows the air to flow freely but the rain doesn’t blow in. I use them spring, summer, and fall and never had a rain issue.

  • Thank you for the reply. Would it be too much trouble to ask for the dimensions of that screened cover?
    Is there such a thing as too much ventilation then during the summer?

  • Hi Rusty,

    I checked on my hive today for the first time in 2 weeks, usually I do a 7-day check, but as a work colleague was away on holidays, and we look after the hive together, I thought of giving them a break from us as well.

    When we opened the hive it was quite evident that our colony had grown substantially from 2 weeks previously. We have 2 brood boxes in the hive, one atop the other, and it was also evident that the colony was only making use of (heavily crowding) the brood frames in the back 5 frames, in both brood boxes.

    They were also storing honey in the brood frames but were not making any use whatsover of the supers. They were building cells prolifically but they were empty, as if they were planning ahead to use them.

    But very noticeable was that our calm and peaceful colony had become very very aggressive, something which they had never been, even stinging my colleague through her gloved hand, a first sting from our hive.

    Could our hive be overheating, hence why they don’t make use of any of the front 7 frames, they being the ones closest to the front of the hive which gets full sun?

    We really really would appreciate any advice. We both love our bees but are very concerned that we are not giving them the best that they require.

    Many thanks,

    • Trevor,

      To start, what kind of hive are you using? A Warre, perhaps, or a National? I ask because you say your bees are using using the back frames instead of the front (Langstroth frames run parallel to the sides). In my experience with a top-bar hive, the bees usually build starting closest to the opening, so I’m not sure why yours would be starting at the back, but the heat is a good guess.

      I also don’t know where you are writing from, but my guess for aggressive bees would be a place where you are experiencing a mid-summer nectar dearth. That would explain both why they are testy and why they are not storing nectar in the supers. If there is no nectar to be had—or very little—they will keep that supply close to where they need it, in the brood box.

      As for the cells, it’s hard to say. Some colonies build them “just because” only to tear them down later. Some colonies actually use them. If you think they are preparing to swarm, watch those cell cups to see if they are raising queens.

  • Hi Rusty,

    I am using a National and am based in London.

    Our hive is in our roof garden and as one of the gardeners, I plan and plant with the bees in mind, ensuring they do have abundant nectar supply, however I have noticed this summer that there is definitely much less flowers in the garden than this time last year.

    Should I supply the hive with syryp to compensate for possible nectar deficiency?

    To date, there are definitely no royal cell cups and I saw the queen moving about one of the brood frames.

    As a precaution I think then that I shall create some shade for the hive as it does get a lot of full sun from about 11 am onwards.

    Many thanks from London, Rusty.


    • Trevor,

      Feeding is a judgement call. If they are still storing nectar, I would not. If they stop storing nectar, and they start using their honey for food, then I would definitely feed.

  • Hi Rusty,

    I’m a new beekeeper this year and I’ve been reading and learning lots on your website so thanks for that.

    I live in a hot part of NC. It’s about 90 to 95 degrees on average. I’ve been noticing an increasing amount of bearding this week. To the point there was a “beard” about 6 inches long across the entire entrance and bees covering the front of the deep and most of a medium. (There is plenty of room for expansion in the hive.)

    I decided to try to increase ventilation with a diy device. Effectively a 4 inch tall super with windows cut out of the sides and covered with screen was placed below the cover. I feel reasonably confident in the design and implementation.

    However, is it possible to provide too much ventilation in the summer? And if so how can I tell if it’s too much.

    Thanks in advance.

    • Jesse,

      I don’t think you can have too much ventilation in the summer. Your idea is good and is similar to something I sometimes use. You should be fine.

  • I’ve been concerned because living in Florida I’m worried about hives overheating.

    I was wondering if anyone tried using a small exhaust fan for a hive, something like those used in laptops. They run on 12 volts and may be workable using a solar cell for power.

  • Rusty

    Do you place the entrance to an inner cover to the rear of the hive or to the front, I have always put to the rear of the hive, but others say it should be to the front.

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