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Why Are They Called “Dog Days” of Summer?

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Why Are They Called “Dog Days” of Summer?

The phrase “Dog Days of Summer” describes the most oppressive period of summer, between July 3rd and August 11th each year. But where did the term come from? And what does it have to do with dogs?

Many people believe the phrase stems from the fact that dogs tend to be sluggish during the hottest days of summer (aren’t we all? ), while others still say the days are so hot it causes dogs to go mad. But the name is actually a reference to the fact that, during this time, the Sun occupies the same region of the sky as Sirius, the brightest star visible from any part of Earth and part of the constellation Canis Major, the Greater Dog. This is why Sirius is sometimes called the Dog Star.

In the summer, Sirius rises and sets with the Sun. On July 23rd, specifically, it is in conjunction with the Sun, and because the star is so bright, the ancient Romans believed it actually gave off heat and added to the Sun’s warmth, accounting for the long stretch of sultry weather. They referred to this time as diēs caniculārēs, or “dog days.”

Thus, the term “Dog Days of Summer” came to mean the 20 days before and 20 days after this alignment of Sirius with the Sun — July 3 to Aug. 11.

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While this period usually is the hottest stretch of summer, the heat is not due to any added radiation from Sirius, regardless of its brightness. The heat of summer is simply a direct result of the Earth’s tilt.

During summer in the Northern Hemisphere, the tilt of the Earth causes the Sun’s rays to hit at a more direct angle, and for a longer period of time throughout the day. This means longer, hotter days.

So what does it mean for you? Plan to take your beach vacation during this time and, of course, search the Farmers’ Almanac web site for great ideas on ways to stay cool!

Natural Ways To Keep Cool This Summer
6 Creative Ways To Keep Cool During Hot Summer Days
Cool Ways To Exercise Safely In Summer
What To Wear When The Temperature Soars
Thirsty? Drink This

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21 comments

1 Susan Higgins { 07.06.17 at 9:02 am }

Hi ann: we agree!

2 ann { 07.05.17 at 4:38 pm }

The dog is so cute you just want to cuddle him or her .

3 Susan Higgins { 07.03.17 at 11:33 am }

Hi Amy, thanks for your note. You should have surgery any time your doctor recommends. But if you’re looking to schedule it during the appropriate phases of the Moon, you can check this chart here:https://farmersalmanac.com/calendar/zodiac/

4 Amy Combs { 07.01.17 at 11:49 pm }

Can you have surgery in dog days and what days

5 Kate T. { 09.15.16 at 7:08 pm }

Found this article because I was checking dog days dates. I just heard my first mockingbird in several weeks so knew it must be over. Connie Mack, are you in North Florida? I see you just heard them too. Can anyone help point me to the reason why mockingbirds stop singing during dog days? I haven’t been able to find research on it

6 Connie Mack { 09.14.16 at 6:00 pm }

Referring to the Mockingbird!

7 Connie Mack { 09.14.16 at 5:58 pm }

The singing stops ! Alerting their young with peeps,and warding off predators with a screech,is all we hear. The singing has started back today! This singing stops for what many call dog days!

8 V. Boggs { 08.18.16 at 7:57 pm }

I always heard and was told if you had a sore or cut to let a dog lick it and it would heal faster! Never tried it!?

9 Nicole { 08.10.16 at 9:55 am }

What exactly does dog days have to do with creek swimming? My parents always told me when I was little I couldn’t swim in the water if it was dog days becUse if I had a sore or anything it would get infected.. Now I tell my kids no swimming in the creek during dog days but why haha … Old wives tale or complete truth?

10 Dan Johnson { 07.23.16 at 11:32 am }

Dog day’s in the south was when you had to watch out for snakes because they are shedding their skins and their eyes would have a bluish color to them due to shedding and couldn’t see or sense as well and would strike at you faster than usual .

11 Larry Parker { 07.06.16 at 8:48 am }

I have heard of the term “New Dog Days” any thing to this?

12 V. Boggs { 08.18.16 at 7:59 pm }

She is right! Rained here the first day and has rained everyday since and is still raining after dog days!

13 Chuck { 07.03.16 at 11:07 pm }

My grandmother always said if it rained the first day of dog days, then it would rain a little everyday for the next 40 days. Conversely, she said that if it didn’t rain the first day of dog days, then it would be dry for the next 40 days. She also said that if dog days set in wet, that if you should have any wounds or open sores during dog days, they would take longer to heal.

14 JW { 07.02.16 at 6:23 pm }

Is there any truth to things that get wet smelling like dog? If so what is the best ways to clean your house without it smelling

15 Pamela { 07.01.15 at 9:54 am }

Makes sense to me! Thanks, Mike!

16 Mindell { 07.12.16 at 10:39 pm }

Is it true that the mocking birds don’t make noises during “Dog Days”??

17 Mike { 07.01.15 at 9:46 am }

Pamala: Every year anglers complain about the “dog days” in mid-to-late summer. The number of boats on the water diminishes as fishing success drops. Anglers are referring to a period of warm water temperatures when seemingly the fish stop biting. Some folks speculate that the fish have sore mouths and have quit feeding. I have heard old timers say, “fish lose their teeth”. There is no scientific or biological evidence of either of those theories. I do know this: Fish are cold-blooded creatures that must eat to survive. The warmer the water, the more they need to eat. The reason anglers aren’t catching has little to do with whether the fish are feeding. They are eating a lot. Fish put on most of their weight during this time.Anglers have good success during those “dog days”. At tournaments, throughout the Midwest, anglers continue to weigh hefty limits of fish. That tells me, most casual anglers simply aren’t applying the right methods to catch fish during the warm water periods. –

18 Traveller1861CS { 07.16.16 at 1:05 pm }

Past wars have proven that wounds do not heal as well. Arizona and New Mexico were two states as well as West Texas were patients with serious respiratory infections were sent in the past.

19 Mike { 07.01.15 at 9:25 am }

Teri Ann
The conjunction of Sirius and the Sun does not occur at the same time in all latitudes, and is not constant in the same region for a long period, hence the variation in calendars regarding the limits of the Dog Days. Some say the period of the dog days lasts 20 days before and after the conjunction of Sirius and the Sun.
In 2015 in the Pacific Time Zone, Sirius rises before the Sun on July 31st, but remains hidden in its glare. When Sirius rises above the Sun at an altitude of 7 degrees it can be seen. This heliacal rising of Sirius occurs August 8, 2015 in San Francisco.

20 Pamela { 07.01.15 at 9:08 am }

Do dog days really affect fishing? I heard it said that during dog days the fish doesn’t bite because something tenders their mouth and makes it difficult for them to eat food…. This may be an old wives tale, but I’m curious to hear you take on it.

21 Teri Ann { 07.01.15 at 8:32 am }

I thought ‘dog days’ happened at a slightly different time each year. Sirius is not in alignment with the sun on July 23 every year. I was hoping you could give me exact dates for this year. This information is hard to find. Thanks.

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