Toronto(KS)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Toronto(KS) clear sky chart from 2005-11-06 to 2026-07-16.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	11% 6% 2 6% 4 4 4 3 5% 7% 48%	138253
	Night	11% 6% 2 5% 4 3 4 3 5% 6% 52%	134774
Transparency	Day	35% 4 11% 26% 20% 4	141891
	Night	32% 4 11% 27% 21% 5%	139203
Seeing	Day	13% 10% 29% 28% 16% 4	17897
	Night	13% 9% 32% 33% 12% 1	27721

By Month

Percentage Cloud Cover SE (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	13% 9% 2 7% 4 4 4 3 4 6% 44%	5289
	11th to 20th	Day	6% 8% 3 7% 5% 5% 4 3 4 6% 49%	5310
	21st to end	Day	12% 11% 3 6% 3 3 3 2 4 5% 47%	5812
February	1st to 10th	Day	14% 8% 4 7% 4 4 3 2 5% 6% 43%	1890
	11th to 20th	Day	11% 8% 3 9% 4 4 4 3 4 5% 45%	1948
	21st to end	Day	10% 8% 2 7% 5% 4 4 4 6% 6% 45%	1749
March	1st to 10th	Day	11% 7% 3 6% 3 3 3 2 3 6% 53%	5046
	11th to 20th	Day	9% 5% 1 4 3 3 4 3 5% 6% 58%	5090
	21st to end	Day	11% 9% 3 8% 5% 4 4 3 6% 7% 39%	5583
April	1st to 10th	Day	12% 7% 2 6% 4 3 4 3 5% 7% 48%	2341
	11th to 20th	Day	15% 7% 3 6% 4 5% 3 3 4 6% 44%	2506
	21st to end	Day	19% 8% 2 6% 4 4 5% 3 5% 5% 39%	2730
May	1st to 10th	Day	17% 7% 2 6% 4 4 3 3 5% 6% 43%	7617
	11th to 20th	Day	11% 5% 2 5% 4 3 4 3 5% 6% 51%	7627
	21st to end	Day	20% 7% 2 6% 4 4 4 4 6% 6% 37%	8392
June	1st to 10th	Day	6% 4 2 5% 5% 5% 5% 4 6% 9% 49%	2730
	11th to 20th	Day	8% 4 2 4 4 4 4 4 6% 8% 50%	2730
	21st to end	Day	6% 4 1 4 3 4 4 4 6% 8% 56%	2730
July	1st to 10th	Day	8% 5% 2 6% 4 5% 5% 4 7% 8% 45%	6030
	11th to 20th	Day	8% 4 2 5% 4 4 5% 4 6% 10% 49%	5966
	21st to end	Day	5% 4 2 6% 5% 5% 6% 5% 8% 11% 42%	6422
August	1st to 10th	Day	5% 4 2 5% 4 4 4 3 6% 8% 54%	4234
	11th to 20th	Day	7% 5% 2 6% 4 5% 5% 4 6% 7% 49%	4171
	21st to end	Day	6% 4 1 4 3 3 4 4 6% 8% 58%	4486
September	1st to 10th	Day	13% 4 2 4 3 3 3 3 4 6% 54%	2283
	11th to 20th	Day	11% 5% 2 5% 4 3 4 3 6% 8% 50%	2200
	21st to end	Day	9% 4 2 5% 3 4 4 2 4 6% 56%	2200
October	1st to 10th	Day	8% 6% 2 6% 4 3 3 3 5% 5% 54%	2057
	11th to 20th	Day	10% 4 1 3 2 3 3 3 4 6% 60%	2000
	21st to end	Day	17% 6% 2 4 3 3 3 2 5% 5% 52%	2200
November	1st to 10th	Day	10% 5% 2 4 2 2 2 2 4 6% 60%	2006
	11th to 20th	Day	10% 5% 1 4 4 3 3 2 4 6% 58%	1890
	21st to end	Day	14% 5% 2 5% 3 2 3 2 4 5% 54%	1890
December	1st to 10th	Day	6% 6% 3 5% 3 3 3 3 3 6% 59%	3030
	11th to 20th	Day	9% 6% 2 6% 4 4 4 3 4 5% 53%	3481
	21st to end	Day	17% 13% 6% 9% 4 4 3 3 4 5% 31%	4587
January	1st to 10th	Night	12% 8% 3 8% 4 3 3 3 4 6% 46%	7634
	11th to 20th	Night	6% 6% 2 6% 5% 4 4 3 4 5% 54%	7680
	21st to end	Night	13% 9% 3 6% 4 4 4 3 4 5% 47%	8402
February	1st to 10th	Night	10% 8% 3 7% 5% 4 4 3 4 6% 45%	2730
	11th to 20th	Night	12% 9% 2 6% 4 4 3 3 4 5% 48%	2575
	21st to end	Night	11% 6% 2 5% 3 3 3 3 6% 6% 51%	2056
March	1st to 10th	Night	14% 6% 2 4 3 3 2 3 4 5% 54%	5029
	11th to 20th	Night	7% 3 1 4 3 3 4 3 5% 6% 62%	5090
	21st to end	Night	12% 6% 3 5% 4 3 4 3 5% 7% 47%	5588
April	1st to 10th	Night	11% 6% 2 5% 4 3 3 3 5% 6% 52%	2279
	11th to 20th	Night	12% 7% 2 6% 4 3 3 2 4 6% 50%	2059
	21st to end	Night	16% 6% 2 6% 3 3 3 3 5% 7% 45%	1890
May	1st to 10th	Night	16% 7% 2 5% 4 3 3 3 5% 7% 47%	5266
	11th to 20th	Night	12% 6% 2 6% 4 3 3 3 4 7% 49%	5265
	21st to end	Night	19% 7% 2 5% 3 3 3 3 4 6% 45%	5793
June	1st to 10th	Night	6% 3 2 4 3 4 5% 5% 6% 10% 52%	1890
	11th to 20th	Night	5% 4 2 4 3 4 4 5% 8% 11% 50%	1890
	21st to end	Night	6% 3 2 5% 3 3 4 4 6% 9% 56%	1890
July	1st to 10th	Night	6% 5% 2 5% 4 4 4 3 6% 9% 54%	4168
	11th to 20th	Night	5% 3 1 5% 4 4 4 3 6% 11% 54%	4122
	21st to end	Night	5% 4 2 6% 5% 5% 6% 5% 8% 10% 44%	4449
August	1st to 10th	Night	2 2 1 4 4 3 4 4 7% 9% 59%	2926
	11th to 20th	Night	7% 4 1 5% 4 4 5% 4 6% 7% 53%	2888
	21st to end	Night	4 2 1 4 3 3 4 3 5% 6% 64%	3416
September	1st to 10th	Night	10% 4 2 4 3 2 3 3 4 6% 59%	2112
	11th to 20th	Night	9% 4 2 5% 3 3 5% 5% 6% 6% 52%	2200
	21st to end	Night	7% 3 1 4 3 3 4 3 5% 6% 60%	2200
October	1st to 10th	Night	9% 5% 1 5% 3 2 3 3 5% 7% 57%	2321
	11th to 20th	Night	11% 4 2 4 3 2 3 2 4 5% 60%	2400
	21st to end	Night	15% 6% 2 4 3 3 3 3 4 5% 54%	2640
November	1st to 10th	Night	10% 5% 1 4 2 3 2 3 4 4 62%	2507
	11th to 20th	Night	9% 6% 1 4 2 3 3 3 4 8% 57%	2730
	21st to end	Night	14% 8% 2 4 3 2 3 2 3 5% 54%	2730
December	1st to 10th	Night	7% 5% 1 4 3 2 3 3 4 5% 62%	4380
	11th to 20th	Night	11% 5% 2 5% 3 3 3 3 4 5% 55%	4946
	21st to end	Night	19% 10% 5% 7% 4 4 3 3 4 5% 36%	6633

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	42% 3 10% 28% 15% 2	5290
	11th to 20th	Day	37% 3 10% 26% 20% 4	5310
	21st to end	Day	42% 2 8% 23% 20% 5%	5812
February	1st to 10th	Day	44% 4 11% 26% 12% 3	1890
	11th to 20th	Day	41% 4 11% 25% 15% 4	1957
	21st to end	Day	38% 5% 9% 22% 19% 7%	1749
March	1st to 10th	Day	36% 3 5% 21% 23% 11%	5046
	11th to 20th	Day	28% 4 9% 22% 24% 14%	5090
	21st to end	Day	43% 6% 12% 28% 10% 1	5585
April	1st to 10th	Day	35% 6% 12% 23% 19% 4	2341
	11th to 20th	Day	41% 4 11% 22% 18% 4	2506
	21st to end	Day	46% 5% 11% 25% 12% 1	2730
May	1st to 10th	Day	43% 4 9% 20% 21% 2	7655
	11th to 20th	Day	34% 5% 9% 25% 24% 4	7631
	21st to end	Day	48% 5% 11% 18% 17% 2	8405
June	1st to 10th	Day	30% 9% 17% 25% 18% 2	2730
	11th to 20th	Day	30% 7% 13% 30% 18% 2	2730
	21st to end	Day	25% 6% 17% 28% 20% 5%	2730
July	1st to 10th	Day	34% 5% 12% 26% 20% 4	5966
	11th to 20th	Day	31% 5% 12% 31% 19% 2	5897
	21st to end	Day	32% 5% 18% 32% 12%	6240
August	1st to 10th	Day	27% 6% 14% 26% 23% 5%	4220
	11th to 20th	Day	34% 5% 17% 26% 17% 2	4210
	21st to end	Day	25% 5% 15% 36% 15% 5%	4485
September	1st to 10th	Day	32% 5% 12% 24% 20% 7%	2283
	11th to 20th	Day	32% 6% 10% 27% 23% 3	2200
	21st to end	Day	31% 5% 9% 23% 29% 5%	2200
October	1st to 10th	Day	21% 4 6% 18% 41% 11%	3343
	11th to 20th	Day	16% 3 5% 31% 33% 11%	3240
	21st to end	Day	29% 3 8% 27% 27% 6%	3538
November	1st to 10th	Day	26% 4 10% 31% 22% 6%	2006
	11th to 20th	Day	30% 4 9% 28% 24% 5%	1890
	21st to end	Day	34% 2 11% 29% 22% 2	1890
December	1st to 10th	Day	29% 4 9% 37% 21% 1	3030
	11th to 20th	Day	34% 3 8% 33% 20% 2	3479
	21st to end	Day	56% 4 10% 21% 8% 1	4587
January	1st to 10th	Night	41% 3 10% 27% 17% 2	7635
	11th to 20th	Night	32% 4 9% 28% 22% 5%	7680
	21st to end	Night	40% 2 10% 21% 22% 4	8402
February	1st to 10th	Night	40% 5% 12% 25% 15% 4	2730
	11th to 20th	Night	39% 3 12% 27% 16% 3	2576
	21st to end	Night	33% 4 8% 24% 22% 8%	2056
March	1st to 10th	Night	34% 4 6% 23% 26% 7%	5029
	11th to 20th	Night	23% 4 7% 20% 35% 11%	5090
	21st to end	Night	36% 5% 15% 28% 14% 2	5588
April	1st to 10th	Night	33% 5% 10% 23% 23% 6%	2279
	11th to 20th	Night	36% 4 12% 23% 19% 6%	2059
	21st to end	Night	38% 6% 14% 23% 17% 3	1890
May	1st to 10th	Night	38% 5% 11% 24% 19% 2	5293
	11th to 20th	Night	36% 4 11% 23% 19% 6%	5266
	21st to end	Night	40% 5% 13% 24% 15% 2	5805
June	1st to 10th	Night	26% 7% 20% 28% 17% 2	1890
	11th to 20th	Night	25% 7% 16% 29% 20% 3	1890
	21st to end	Night	24% 6% 15% 31% 20% 4	1890
July	1st to 10th	Night	28% 5% 14% 28% 22% 3	4125
	11th to 20th	Night	25% 4 12% 37% 19% 2	4071
	21st to end	Night	32% 5% 19% 33% 11% 1	4320
August	1st to 10th	Night	21% 5% 16% 31% 19% 9%	2916
	11th to 20th	Night	29% 5% 15% 28% 20% 3	2915
	21st to end	Night	20% 4 14% 38% 19% 5%	3416
September	1st to 10th	Night	27% 5% 11% 27% 20% 10%	2112
	11th to 20th	Night	30% 6% 11% 24% 24% 5%	2200
	21st to end	Night	24% 5% 10% 25% 31% 6%	2200
October	1st to 10th	Night	18% 3 6% 15% 46% 13%	3802
	11th to 20th	Night	20% 2 5% 24% 33% 15%	3899
	21st to end	Night	28% 4 7% 26% 31% 5%	4252
November	1st to 10th	Night	26% 3 9% 29% 25% 7%	2507
	11th to 20th	Night	28% 4 8% 26% 28% 5%	2730
	21st to end	Night	35% 3 9% 25% 22% 5%	2730
December	1st to 10th	Night	25% 4 13% 39% 19% 1	4380
	11th to 20th	Night	32% 3 9% 30% 22% 4	4947
	21st to end	Night	49% 4 9% 25% 10% 2	6633

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	19% 13% 36% 26% 7%	330
	11th to 20th	Day	20% 18% 39% 18% 4	330
	21st to end	Day	11% 14% 48% 23% 2 1	363
February	1st to 10th	Day	22% 17% 35% 20% 5% 1	330
	11th to 20th	Day	16% 18% 41% 20% 5%	330
	21st to end	Day	14% 22% 42% 16% 4	273
March	1st to 10th	Day	19% 19% 37% 22% 4	330
	11th to 20th	Day	22% 17% 34% 22% 5% 1	330
	21st to end	Day	21% 23% 37% 17% 2 1	363
April	1st to 10th	Day	19% 20% 36% 21% 4	361
	11th to 20th	Day	21% 17% 37% 20% 4	544
	21st to end	Day	22% 16% 36% 19% 7% 1	750
May	1st to 10th	Day	18% 12% 36% 23% 9% 1	753
	11th to 20th	Day	17% 13% 30% 25% 12% 2	775
	21st to end	Day	19% 8% 30% 24% 16% 3	844
June	1st to 10th	Day	6% 6% 24% 33% 25% 6%	780
	11th to 20th	Day	9% 4 30% 37% 17% 3	780
	21st to end	Day	6% 5% 31% 38% 18% 2	780
July	1st to 10th	Day	9% 3 17% 33% 29% 9%	771
	11th to 20th	Day	5% 2 15% 39% 32% 7%	744
	21st to end	Day	7% 3 12% 37% 31% 10%	794
August	1st to 10th	Day	7% 3 17% 38% 29% 6%	726
	11th to 20th	Day	7% 2 17% 36% 31% 7%	715
	21st to end	Day	9% 1 14% 33% 34% 9%	692
September	1st to 10th	Day	14% 2 11% 34% 32% 7%	413
	11th to 20th	Day	6% 2 18% 38% 28% 8%	330
	21st to end	Day	14% 4 22% 34% 18% 7%	330
October	1st to 10th	Day	13% 5% 26% 31% 17% 8%	330
	11th to 20th	Day	9% 10% 45% 27% 9%	330
	21st to end	Day	26% 11% 32% 21% 9% 1	363
November	1st to 10th	Day	15% 12% 36% 24% 11% 2	330
	11th to 20th	Day	16% 15% 35% 20% 11% 2	330
	21st to end	Day	19% 12% 39% 20% 9%	330
December	1st to 10th	Day	11% 12% 41% 25% 8% 2	330
	11th to 20th	Day	15% 14% 37% 24% 8% 1	330
	21st to end	Day	17% 22% 35% 21% 5%	363
January	1st to 10th	Night	12% 13% 39% 30% 6%	1050
	11th to 20th	Night	14% 13% 39% 28% 6%	1050
	21st to end	Night	13% 12% 39% 30% 5%	1155
February	1st to 10th	Night	15% 14% 40% 27% 4	1050
	11th to 20th	Night	17% 14% 39% 27% 2	941
	21st to end	Night	14% 14% 40% 27% 5%	672
March	1st to 10th	Night	16% 12% 40% 28% 4	630
	11th to 20th	Night	17% 13% 37% 27% 6%	630
	21st to end	Night	19% 14% 41% 22% 3	693
April	1st to 10th	Night	15% 13% 41% 26% 5%	630
	11th to 20th	Night	17% 16% 39% 25% 5%	623
	21st to end	Night	18% 12% 37% 26% 6% 1	630
May	1st to 10th	Night	18% 8% 35% 31% 6% 1	630
	11th to 20th	Night	15% 7% 31% 32% 15%	621
	21st to end	Night	13% 6% 29% 32% 17% 2	683
June	1st to 10th	Night	7% 4 23% 43% 23% 1	630
	11th to 20th	Night	5% 4 29% 44% 17%	630
	21st to end	Night	5% 4 34% 43% 13%	630
July	1st to 10th	Night	7% 2 17% 43% 29% 2	615
	11th to 20th	Night	2 2 16% 51% 27% 2	597
	21st to end	Night	6% 2 15% 44% 30% 2	657
August	1st to 10th	Night	4 2 19% 46% 28% 1	597
	11th to 20th	Night	7% 2 15% 47% 28% 1	594
	21st to end	Night	5% 1 14% 41% 37% 3	660
September	1st to 10th	Night	12% 2 17% 44% 23% 2	600
	11th to 20th	Night	11% 2 23% 38% 24% 3	600
	21st to end	Night	9% 5% 22% 41% 20% 3	600
October	1st to 10th	Night	12% 4 26% 36% 21% 2	721
	11th to 20th	Night	13% 8% 38% 33% 7%	800
	21st to end	Night	18% 13% 32% 28% 9%	880
November	1st to 10th	Night	12% 9% 38% 29% 11% 1	867
	11th to 20th	Night	12% 12% 36% 32% 8%	1050
	21st to end	Night	18% 13% 30% 31% 8%	1050
December	1st to 10th	Night	14% 10% 36% 32% 6%	1050
	11th to 20th	Night	17% 11% 36% 31% 4	1050
	21st to end	Night	17% 14% 34% 29% 5%	1155

Page generated at 2026-07-13 02:14:53. Version ac07

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