Radar de Saint-Adolphe-d'Howard
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Radar de Saint-Adolphe-d'Howard clear sky chart from 2005-11-06 to 2026-01-17.

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	17% 11% 4 9% 5% 5% 5% 4 5% 6% 30%	127668
	Night	15% 12% 4 10% 6% 4 4 3 5% 6% 30%	124002
Transparency	Day	52% 7% 11% 19% 10% 1	131100
	Night	52% 8% 11% 18% 10% 1	128657
Seeing	Day	25% 19% 31% 17% 6% 2	15925
	Night	22% 16% 30% 23% 8% 1	25003

By Month

Percentage Cloud Cover NE (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	12% 23% 6% 14% 6% 5% 6% 3 4 4 18%	3677
	11th to 20th	Day	10% 16% 7% 17% 10% 5% 5% 3 3 4 19%	3618
	21st to end	Day	7% 15% 8% 16% 7% 5% 5% 4 4 5% 24%	3960
February	1st to 10th	Day	11% 18% 5% 13% 9% 4 4 3 4 6% 23%	1774
	11th to 20th	Day	12% 18% 5% 12% 6% 6% 4 4 4 5% 24%	1819
	21st to end	Day	15% 18% 5% 10% 6% 5% 5% 3 4 5% 24%	1650
March	1st to 10th	Day	16% 16% 6% 13% 8% 4 4 3 4 4 23%	4476
	11th to 20th	Day	10% 15% 5% 12% 5% 5% 4 4 5% 7% 29%	4768
	21st to end	Day	17% 13% 4 9% 5% 4 3 3 4 5% 33%	5918
April	1st to 10th	Day	20% 14% 4 8% 5% 3 3 3 4 5% 31%	2400
	11th to 20th	Day	21% 11% 3 7% 4 4 4 3 4 5% 33%	2374
	21st to end	Day	22% 11% 4 8% 5% 4 5% 4 4 5% 30%	2554
May	1st to 10th	Day	25% 11% 4 9% 5% 5% 4 3 5% 5% 22%	6346
	11th to 20th	Day	20% 9% 3 8% 5% 5% 5% 4 6% 7% 29%	6318
	21st to end	Day	23% 9% 3 7% 5% 5% 4 3 5% 6% 29%	6949
June	1st to 10th	Day	21% 9% 3 8% 5% 4 5% 4 6% 7% 27%	2800
	11th to 20th	Day	16% 7% 3 8% 5% 5% 5% 5% 6% 8% 33%	2800
	21st to end	Day	23% 9% 3 8% 5% 5% 4 5% 6% 6% 27%	2800
July	1st to 10th	Day	15% 7% 3 9% 7% 6% 6% 5% 6% 7% 29%	6360
	11th to 20th	Day	13% 6% 2 7% 5% 5% 5% 5% 7% 8% 38%	6360
	21st to end	Day	10% 6% 2 6% 4 5% 5% 4 6% 9% 43%	6926
August	1st to 10th	Day	15% 6% 3 8% 6% 5% 6% 5% 6% 8% 32%	4563
	11th to 20th	Day	16% 7% 3 7% 5% 4 5% 4 7% 8% 35%	4148
	21st to end	Day	16% 5% 3 6% 5% 5% 5% 4 6% 8% 36%	4312
September	1st to 10th	Day	15% 6% 2 6% 4 4 5% 4 5% 8% 40%	2400
	11th to 20th	Day	14% 5% 3 6% 4 4 4 3 4 7% 46%	2340
	21st to end	Day	20% 7% 3 5% 4 4 4 4 5% 6% 40%	2200
October	1st to 10th	Day	21% 8% 2 6% 5% 4 4 3 5% 7% 35%	2025
	11th to 20th	Day	22% 11% 3 9% 5% 5% 4 4 5% 6% 28%	1975
	21st to end	Day	25% 12% 3 9% 5% 4 3 3 5% 6% 26%	1980
November	1st to 10th	Day	15% 13% 5% 8% 5% 4 5% 4 5% 6% 31%	1851
	11th to 20th	Day	18% 14% 5% 9% 5% 4 5% 3 6% 5% 25%	1753
	21st to end	Day	21% 16% 5% 10% 6% 4 4 4 5% 5% 20%	1680
December	1st to 10th	Day	17% 19% 8% 14% 4 5% 4 3 4 4 16%	2680
	11th to 20th	Day	16% 16% 7% 13% 6% 5% 4 3 4 4 23%	3066
	21st to end	Day	18% 16% 7% 10% 4 4 4 3 4 4 24%	4048
January	1st to 10th	Night	10% 23% 10% 13% 5% 4 4 3 4 5% 19%	6489
	11th to 20th	Night	7% 14% 8% 20% 9% 5% 5% 3 4 5% 20%	6400
	21st to end	Night	8% 13% 7% 17% 8% 6% 5% 3 5% 6% 23%	6996
February	1st to 10th	Night	11% 15% 5% 11% 7% 5% 5% 4 5% 5% 25%	2625
	11th to 20th	Night	11% 15% 5% 13% 6% 5% 4 4 5% 5% 26%	2465
	21st to end	Night	11% 16% 5% 12% 6% 5% 4 4 4 6% 27%	1980
March	1st to 10th	Night	19% 14% 5% 11% 5% 4 4 3 4 4 27%	5364
	11th to 20th	Night	10% 15% 4 10% 4 5% 5% 4 6% 8% 29%	5175
	21st to end	Night	15% 12% 4 9% 5% 5% 5% 3 5% 5% 31%	5013
April	1st to 10th	Night	21% 12% 4 6% 5% 4 4 3 4 6% 31%	2000
	11th to 20th	Night	18% 8% 3 7% 6% 4 5% 3 5% 5% 36%	1975
	21st to end	Night	21% 9% 2 8% 4 4 4 4 5% 5% 34%	1856
May	1st to 10th	Night	21% 10% 4 9% 6% 4 5% 4 6% 5% 26%	3599
	11th to 20th	Night	20% 8% 3 7% 5% 4 4 3 5% 7% 34%	3575
	21st to end	Night	21% 10% 3 7% 5% 4 5% 4 6% 7% 29%	3926
June	1st to 10th	Night	19% 9% 2 7% 4 4 5% 4 6% 9% 31%	1600
	11th to 20th	Night	17% 7% 2 6% 5% 4 4 4 5% 7% 38%	1600
	21st to end	Night	21% 7% 2 5% 5% 5% 5% 4 5% 6% 36%	1600
July	1st to 10th	Night	14% 6% 3 8% 6% 5% 5% 5% 7% 7% 34%	3600
	11th to 20th	Night	13% 7% 3 7% 4 4 4 3 5% 7% 43%	3600
	21st to end	Night	9% 5% 2 6% 4 4 5% 4 7% 8% 47%	3926
August	1st to 10th	Night	12% 6% 3 8% 5% 4 5% 4 6% 8% 40%	2586
	11th to 20th	Night	14% 7% 3 8% 5% 3 4 3 5% 6% 42%	2862
	21st to end	Night	16% 6% 2 6% 5% 4 4 3 5% 7% 42%	3586
September	1st to 10th	Night	11% 6% 3 6% 4 4 4 4 5% 7% 47%	2000
	11th to 20th	Night	14% 5% 2 5% 3 3 3 3 5% 7% 49%	2060
	21st to end	Night	18% 6% 2 5% 3 3 4 3 5% 7% 44%	2200
October	1st to 10th	Night	16% 7% 3 7% 5% 4 4 4 4 5% 41%	2371
	11th to 20th	Night	20% 9% 3 8% 4 4 4 3 5% 6% 33%	2424
	21st to end	Night	22% 10% 3 8% 5% 4 4 3 5% 7% 29%	2860
November	1st to 10th	Night	18% 10% 4 9% 5% 4 4 4 6% 6% 29%	2667
	11th to 20th	Night	17% 12% 4 10% 5% 5% 5% 4 5% 6% 29%	2864
	21st to end	Night	18% 17% 5% 10% 7% 4 4 3 5% 5% 23%	2940
December	1st to 10th	Night	15% 15% 6% 12% 7% 6% 5% 4 5% 7% 19%	4720
	11th to 20th	Night	21% 13% 5% 12% 7% 4 4 2 3 4 24%	5348
	21st to end	Night	20% 20% 5% 9% 5% 3 3 2 3 4 27%	7150

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	67% 9% 7% 13% 4	3678
	11th to 20th	Day	63% 10% 4 13% 7% 2	3648
	21st to end	Day	60% 9% 7% 12% 12% 1	3960
February	1st to 10th	Day	62% 5% 6% 16% 8% 2	1774
	11th to 20th	Day	61% 6% 10% 14% 9% 1	1828
	21st to end	Day	61% 5% 7% 14% 10% 2	1650
March	1st to 10th	Day	64% 5% 6% 10% 12% 3	4479
	11th to 20th	Day	52% 8% 15% 12% 11% 2	4768
	21st to end	Day	53% 4 7% 15% 18% 2	5918
April	1st to 10th	Day	55% 5% 9% 16% 12% 3	2400
	11th to 20th	Day	52% 6% 8% 19% 13% 2	2374
	21st to end	Day	56% 6% 7% 16% 12% 3	2554
May	1st to 10th	Day	62% 6% 7% 17% 7% 1	6357
	11th to 20th	Day	52% 8% 14% 16% 8% 2	6322
	21st to end	Day	54% 7% 10% 17% 12% 1	6949
June	1st to 10th	Day	54% 8% 8% 17% 11% 1	2800
	11th to 20th	Day	46% 8% 12% 21% 11% 3	2800
	21st to end	Day	56% 8% 10% 17% 9% 1	2800
July	1st to 10th	Day	50% 8% 12% 23% 6%	6290
	11th to 20th	Day	39% 8% 14% 30% 8%	6285
	21st to end	Day	35% 7% 17% 32% 9%	6728
August	1st to 10th	Day	46% 8% 16% 22% 7%	4549
	11th to 20th	Day	43% 9% 15% 27% 6%	4190
	21st to end	Day	44% 7% 15% 21% 12% 1	4312
September	1st to 10th	Day	40% 7% 13% 27% 12%	2400
	11th to 20th	Day	36% 8% 13% 30% 12% 1	2340
	21st to end	Day	44% 6% 12% 25% 12% 1	2200
October	1st to 10th	Day	44% 7% 12% 27% 9%	3298
	11th to 20th	Day	47% 7% 15% 23% 8% 1	3191
	21st to end	Day	48% 8% 20% 15% 8% 1	3180
November	1st to 10th	Day	53% 7% 13% 18% 8% 1	1851
	11th to 20th	Day	58% 9% 11% 12% 10% 1	1753
	21st to end	Day	64% 8% 11% 12% 4 1	1680
December	1st to 10th	Day	69% 7% 8% 12% 4	2680
	11th to 20th	Day	62% 7% 7% 15% 9%	3066
	21st to end	Day	63% 5% 8% 15% 10%	4048
January	1st to 10th	Night	66% 8% 10% 12% 4	6489
	11th to 20th	Night	63% 10% 9% 12% 5% 1	6445
	21st to end	Night	60% 9% 8% 9% 14% 1	6996
February	1st to 10th	Night	58% 7% 9% 17% 8% 1	2625
	11th to 20th	Night	56% 8% 10% 16% 8% 1	2467
	21st to end	Night	56% 7% 9% 16% 10% 2	1980
March	1st to 10th	Night	60% 5% 8% 11% 13% 3	5374
	11th to 20th	Night	51% 8% 13% 15% 10% 3	5176
	21st to end	Night	53% 5% 9% 19% 11% 3	5013
April	1st to 10th	Night	54% 5% 8% 17% 14% 2	2000
	11th to 20th	Night	49% 6% 8% 21% 14% 2	1975
	21st to end	Night	50% 6% 9% 19% 13% 3	1856
May	1st to 10th	Night	56% 8% 10% 18% 7% 2	3605
	11th to 20th	Night	48% 8% 14% 17% 10% 2	3576
	21st to end	Night	54% 7% 9% 17% 12% 1	3927
June	1st to 10th	Night	48% 8% 12% 21% 12%	1600
	11th to 20th	Night	45% 7% 10% 22% 13% 3	1600
	21st to end	Night	48% 8% 11% 19% 13% 1	1600
July	1st to 10th	Night	46% 8% 18% 21% 7%	3560
	11th to 20th	Night	37% 8% 18% 30% 6%	3552
	21st to end	Night	34% 6% 17% 30% 12%	3809
August	1st to 10th	Night	40% 9% 15% 27% 8%	2576
	11th to 20th	Night	40% 9% 17% 26% 8%	2886
	21st to end	Night	41% 7% 15% 24% 11% 2	3586
September	1st to 10th	Night	36% 8% 14% 28% 14% 1	2000
	11th to 20th	Night	34% 7% 15% 33% 11% 1	2060
	21st to end	Night	40% 8% 11% 28% 14%	2200
October	1st to 10th	Night	43% 8% 13% 24% 12% 1	3878
	11th to 20th	Night	44% 8% 13% 25% 11%	3947
	21st to end	Night	46% 7% 18% 16% 10% 1	4610
November	1st to 10th	Night	53% 8% 13% 19% 6% 1	2667
	11th to 20th	Night	53% 9% 11% 16% 9% 2	2864
	21st to end	Night	60% 9% 10% 14% 6% 1	2940
December	1st to 10th	Night	62% 9% 10% 14% 4	4720
	11th to 20th	Night	63% 6% 6% 14% 10% 1	5348
	21st to end	Night	63% 5% 5% 12% 14% 1	7150

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	20% 27% 36% 13% 4	220
	11th to 20th	Day	29% 24% 34% 8% 5%	212
	21st to end	Day	21% 27% 34% 13% 4 1	220
February	1st to 10th	Day	36% 32% 26% 6% 1	287
	11th to 20th	Day	27% 32% 34% 7% 1	366
	21st to end	Day	29% 25% 31% 13% 1	414
March	1st to 10th	Day	29% 23% 32% 13% 3	500
	11th to 20th	Day	26% 25% 33% 13% 3 1	500
	21st to end	Day	32% 24% 25% 15% 5% 1	550
April	1st to 10th	Day	35% 21% 27% 13% 4 1	500
	11th to 20th	Day	36% 21% 24% 12% 7% 1	492
	21st to end	Day	32% 21% 30% 12% 3 1	500
May	1st to 10th	Day	27% 23% 30% 14% 4 1	503
	11th to 20th	Day	24% 19% 32% 19% 5% 1	527
	21st to end	Day	27% 20% 31% 17% 5%	573
June	1st to 10th	Day	25% 19% 34% 16% 5%	530
	11th to 20th	Day	18% 21% 35% 17% 8% 1	530
	21st to end	Day	27% 15% 35% 16% 6% 2	530
July	1st to 10th	Day	17% 13% 36% 23% 9% 2	525
	11th to 20th	Day	17% 14% 37% 25% 6% 1	524
	21st to end	Day	15% 13% 36% 27% 8% 1	576
August	1st to 10th	Day	17% 10% 30% 30% 11% 2	526
	11th to 20th	Day	16% 9% 27% 31% 13% 5%	519
	21st to end	Day	18% 16% 29% 21% 11% 5%	583
September	1st to 10th	Day	19% 13% 32% 22% 10% 4	530
	11th to 20th	Day	12% 13% 27% 25% 15% 8%	530
	21st to end	Day	22% 15% 25% 23% 10% 4	530
October	1st to 10th	Day	25% 18% 26% 19% 10% 2	530
	11th to 20th	Day	28% 22% 28% 16% 5% 1	516
	21st to end	Day	33% 16% 29% 18% 4	462
November	1st to 10th	Day	32% 20% 28% 15% 4 1	425
	11th to 20th	Day	27% 24% 32% 13% 4	293
	21st to end	Day	33% 27% 29% 10% 1	220
December	1st to 10th	Day	28% 24% 31% 13% 5%	220
	11th to 20th	Day	31% 26% 32% 10% 1	220
	21st to end	Day	31% 26% 27% 11% 2 2	242
January	1st to 10th	Night	23% 20% 37% 17% 3	840
	11th to 20th	Night	25% 24% 28% 18% 4	825
	21st to end	Night	16% 20% 38% 20% 5% 1	880
February	1st to 10th	Night	20% 23% 34% 19% 3 1	800
	11th to 20th	Night	21% 23% 37% 16% 3	783
	21st to end	Night	23% 19% 34% 22% 3	660
March	1st to 10th	Night	24% 20% 34% 19% 4	800
	11th to 20th	Night	24% 21% 32% 18% 4 1	800
	21st to end	Night	23% 19% 30% 22% 5% 1	880
April	1st to 10th	Night	29% 17% 28% 22% 4	800
	11th to 20th	Night	24% 17% 31% 22% 5% 1	791
	21st to end	Night	28% 16% 31% 18% 7%	656
May	1st to 10th	Night	25% 13% 33% 21% 6% 1	405
	11th to 20th	Night	22% 13% 29% 27% 8% 1	394
	21st to end	Night	21% 10% 36% 25% 6%	433
June	1st to 10th	Night	23% 9% 32% 28% 8%	400
	11th to 20th	Night	24% 8% 25% 31% 11% 1	400
	21st to end	Night	23% 7% 26% 31% 14% 1	400
July	1st to 10th	Night	13% 10% 26% 35% 14% 1	390
	11th to 20th	Night	12% 7% 26% 40% 14% 1	388
	21st to end	Night	13% 7% 26% 39% 13% 1	438
August	1st to 10th	Night	13% 5% 23% 41% 17% 1	398
	11th to 20th	Night	12% 6% 25% 32% 24% 1	578
	21st to end	Night	17% 8% 26% 32% 15% 2	880
September	1st to 10th	Night	13% 10% 30% 32% 14% 1	800
	11th to 20th	Night	16% 8% 23% 31% 21% 2	800
	21st to end	Night	20% 10% 25% 27% 16% 2	800
October	1st to 10th	Night	21% 11% 30% 25% 12% 1	800
	11th to 20th	Night	25% 14% 31% 23% 7% 1	800
	21st to end	Night	28% 16% 29% 22% 5%	880
November	1st to 10th	Night	27% 18% 27% 22% 5% 1	820
	11th to 20th	Night	24% 20% 30% 18% 8% 1	840
	21st to end	Night	29% 22% 26% 18% 5% 1	840
December	1st to 10th	Night	27% 20% 31% 16% 5%	840
	11th to 20th	Night	29% 24% 26% 16% 4 1	840
	21st to end	Night	32% 20% 28% 16% 4	924

Page generated at 2026-01-14 01:14:25. Version ac07

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