Havre-Saint-Pierre
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Havre-Saint-Pierre clear sky chart from 2005-11-06 to 2024-12-06.

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	19% 10% 3 7% 4 4 4 3 5% 6% 34%	102123
	Night	19% 12% 4 8% 5% 4 4 3 5% 6% 31%	97708
Transparency	Day	50% 7% 14% 20% 8% 1	105560
	Night	53% 7% 12% 18% 9% 1	102367
Seeing	Day	24% 7% 23% 29% 15% 3	16816
	Night	24% 8% 26% 29% 12% 2	24161

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% 13% 5% 11% 4 4 3 2 3 4 41%	2207
	11th to 20th	Day	13% 18% 6% 12% 6% 4 5% 3 4 7% 23%	2210
	21st to end	Day	8% 10% 4 9% 5% 5% 4 4 6% 7% 38%	2612
February	1st to 10th	Day	10% 13% 4 11% 6% 5% 5% 4 5% 5% 33%	1710
	11th to 20th	Day	11% 14% 4 10% 6% 6% 4 3 5% 6% 30%	1663
	21st to end	Day	10% 13% 5% 8% 5% 5% 4 4 4 5% 36%	1413
March	1st to 10th	Day	9% 11% 5% 10% 6% 6% 5% 4 5% 6% 33%	3254
	11th to 20th	Day	21% 21% 5% 9% 5% 4 4 3 3 4 20%	3480
	21st to end	Day	23% 14% 3 8% 4 4 4 3 4 5% 29%	3893
April	1st to 10th	Day	22% 14% 4 7% 4 5% 4 3 4 6% 28%	2280
	11th to 20th	Day	16% 11% 3 6% 4 4 4 3 5% 6% 38%	2414
	21st to end	Day	24% 10% 3 5% 4 3 3 2 4 5% 37%	2524
May	1st to 10th	Day	29% 10% 3 8% 4 4 4 3 5% 6% 25%	4425
	11th to 20th	Day	15% 7% 3 7% 5% 4 5% 4 6% 7% 37%	4398
	21st to end	Day	31% 11% 3 7% 3 3 3 3 4 5% 26%	5142
June	1st to 10th	Day	26% 8% 3 7% 4 4 4 3 5% 6% 31%	2850
	11th to 20th	Day	22% 6% 2 5% 5% 4 3 4 6% 7% 34%	2850
	21st to end	Day	23% 8% 2 7% 4 4 4 4 5% 7% 32%	2850
July	1st to 10th	Day	13% 7% 2 8% 5% 5% 5% 4 6% 6% 38%	4760
	11th to 20th	Day	14% 7% 3 7% 5% 5% 5% 4 7% 8% 35%	4760
	21st to end	Day	16% 5% 2 5% 3 3 4 3 6% 8% 45%	5023
August	1st to 10th	Day	15% 5% 2 6% 4 4 4 4 7% 8% 40%	4401
	11th to 20th	Day	20% 10% 4 9% 5% 5% 5% 3 6% 6% 27%	4045
	21st to end	Day	14% 5% 2 5% 4 3 4 3 6% 8% 45%	4468
September	1st to 10th	Day	21% 5% 2 6% 4 4 5% 4 5% 6% 39%	2280
	11th to 20th	Day	24% 7% 2 6% 3 2 3 3 4 5% 40%	2252
	21st to end	Day	22% 6% 2 6% 4 3 4 4 4 5% 40%	2003
October	1st to 10th	Day	19% 7% 2 6% 4 4 4 4 5% 6% 39%	1900
	11th to 20th	Day	25% 7% 2 6% 3 4 4 4 5% 7% 33%	1900
	21st to end	Day	23% 11% 3 8% 5% 3 3 2 4 5% 33%	1867
November	1st to 10th	Day	22% 10% 3 8% 4 4 4 3 4 6% 32%	1565
	11th to 20th	Day	24% 15% 3 6% 4 4 4 3 4 5% 28%	1600
	21st to end	Day	24% 15% 4 8% 5% 3 4 2 4 4 27%	1600
December	1st to 10th	Day	18% 15% 4 8% 6% 4 4 3 4 6% 27%	1425
	11th to 20th	Day	19% 13% 6% 8% 4 6% 5% 3 4 5% 26%	1668
	21st to end	Day	12% 14% 4 8% 4 5% 4 3 4 6% 35%	2431
January	1st to 10th	Night	11% 15% 5% 9% 6% 4 3 3 4 6% 35%	4748
	11th to 20th	Night	17% 15% 6% 9% 5% 3 4 3 5% 7% 25%	4760
	21st to end	Night	7% 12% 5% 12% 6% 4 4 3 5% 6% 37%	5050
February	1st to 10th	Night	9% 15% 5% 10% 5% 5% 4 3 5% 6% 31%	2470
	11th to 20th	Night	12% 16% 5% 8% 5% 5% 5% 3 5% 5% 30%	2403
	21st to end	Night	10% 15% 5% 9% 6% 6% 4 4 4 6% 31%	2041
March	1st to 10th	Night	10% 11% 4 9% 6% 5% 4 3 5% 6% 36%	3581
	11th to 20th	Night	19% 20% 5% 10% 5% 4 4 3 4 4 20%	3479
	21st to end	Night	24% 16% 4 7% 4 4 3 3 4 4 27%	3738
April	1st to 10th	Night	22% 13% 3 8% 5% 4 5% 3 5% 5% 26%	1900
	11th to 20th	Night	19% 11% 3 6% 4 5% 3 4 4 5% 37%	1712
	21st to end	Night	24% 9% 4 6% 5% 3 4 3 4 5% 33%	1655
May	1st to 10th	Night	32% 10% 3 7% 4 4 3 3 5% 6% 23%	2525
	11th to 20th	Night	16% 8% 3 7% 5% 5% 4 4 5% 6% 38%	2506
	21st to end	Night	27% 10% 3 7% 5% 4 4 3 5% 5% 25%	2473
June	1st to 10th	Night	26% 7% 2 6% 5% 5% 5% 4 5% 7% 29%	1330
	11th to 20th	Night	23% 8% 2 5% 4 4 4 3 6% 8% 32%	1330
	21st to end	Night	26% 8% 3 7% 6% 5% 4 4 4 5% 28%	1330
July	1st to 10th	Night	20% 9% 3 7% 5% 4 5% 3 5% 7% 33%	2210
	11th to 20th	Night	17% 11% 3 7% 4 4 5% 4 5% 7% 33%	2210
	21st to end	Night	16% 7% 3 5% 3 4 4 4 5% 8% 42%	2496
August	1st to 10th	Night	14% 9% 3 8% 5% 4 4 4 6% 8% 33%	2536
	11th to 20th	Night	19% 7% 3 8% 5% 5% 5% 3 5% 6% 34%	2782
	21st to end	Night	18% 7% 3 8% 4 5% 4 3 5% 7% 37%	3188
September	1st to 10th	Night	24% 7% 2 5% 4 4 2 4 5% 6% 39%	1900
	11th to 20th	Night	23% 6% 2 7% 4 4 4 3 4 6% 38%	1924
	21st to end	Night	24% 7% 2 5% 3 4 4 3 5% 6% 37%	2176
October	1st to 10th	Night	24% 9% 2 6% 5% 4 4 3 5% 5% 35%	2280
	11th to 20th	Night	29% 8% 3 6% 4 3 4 3 4 4 31%	2280
	21st to end	Night	25% 9% 3 7% 4 4 3 3 5% 6% 32%	2725
November	1st to 10th	Night	24% 11% 3 7% 4 3 4 4 4 5% 31%	2733
	11th to 20th	Night	26% 14% 4 7% 4 4 3 3 4 4 26%	2800
	21st to end	Night	25% 17% 4 7% 5% 3 4 3 4 4 25%	2800
December	1st to 10th	Night	19% 16% 5% 8% 6% 4 3 3 4 5% 26%	2870
	11th to 20th	Night	23% 13% 5% 8% 4 4 3 3 5% 5% 26%	3531
	21st to end	Night	13% 15% 4 7% 4 4 4 3 5% 6% 33%	5236

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	50% 6% 7% 19% 15% 2	2208
	11th to 20th	Day	60% 14% 9% 12% 4 1	2210
	21st to end	Day	44% 12% 13% 12% 14% 5%	2612
February	1st to 10th	Day	53% 7% 10% 17% 11% 1	1710
	11th to 20th	Day	57% 6% 10% 17% 10%	1671
	21st to end	Day	51% 6% 11% 20% 11% 1	1413
March	1st to 10th	Day	51% 7% 13% 17% 12% 1	3258
	11th to 20th	Day	68% 4 8% 11% 8% 1	3480
	21st to end	Day	58% 5% 10% 18% 8% 2	3893
April	1st to 10th	Day	57% 6% 12% 13% 11% 2	2280
	11th to 20th	Day	47% 6% 11% 22% 13% 2	2414
	21st to end	Day	51% 4 14% 18% 12% 1	2524
May	1st to 10th	Day	58% 6% 12% 19% 5%	4440
	11th to 20th	Day	44% 7% 15% 25% 9% 1	4402
	21st to end	Day	59% 5% 11% 18% 6% 1	5142
June	1st to 10th	Day	54% 6% 13% 18% 9% 1	2850
	11th to 20th	Day	47% 7% 14% 22% 10% 1	2850
	21st to end	Day	52% 8% 12% 20% 8%	2850
July	1st to 10th	Day	44% 6% 13% 27% 9%	4685
	11th to 20th	Day	44% 8% 18% 23% 7%	4679
	21st to end	Day	37% 6% 20% 29% 8%	4863
August	1st to 10th	Day	40% 8% 21% 27% 4	4387
	11th to 20th	Day	55% 6% 17% 16% 5%	4084
	21st to end	Day	36% 6% 19% 29% 11%	4468
September	1st to 10th	Day	45% 6% 16% 24% 9%	2280
	11th to 20th	Day	46% 6% 17% 22% 8%	2252
	21st to end	Day	45% 6% 15% 23% 10%	2003
October	1st to 10th	Day	50% 6% 14% 25% 5%	3160
	11th to 20th	Day	51% 5% 15% 22% 6%	3140
	21st to end	Day	50% 4 13% 19% 14%	3063
November	1st to 10th	Day	56% 7% 12% 15% 10%	1565
	11th to 20th	Day	61% 6% 10% 15% 7% 1	1600
	21st to end	Day	62% 7% 9% 15% 7%	1600
December	1st to 10th	Day	59% 9% 11% 16% 4 1	1425
	11th to 20th	Day	60% 10% 10% 13% 6% 1	1668
	21st to end	Day	50% 10% 11% 16% 10% 3	2431
January	1st to 10th	Night	53% 7% 9% 19% 12% 1	4748
	11th to 20th	Night	59% 12% 8% 15% 7% 1	4760
	21st to end	Night	46% 10% 12% 17% 14% 1	5050
February	1st to 10th	Night	53% 9% 9% 16% 11% 2	2470
	11th to 20th	Night	55% 6% 10% 17% 11% 1	2406
	21st to end	Night	54% 6% 9% 17% 11% 2	2041
March	1st to 10th	Night	47% 8% 12% 20% 12% 1	3590
	11th to 20th	Night	67% 5% 9% 10% 8% 1	3480
	21st to end	Night	60% 5% 9% 14% 7% 5%	3738
April	1st to 10th	Night	61% 5% 8% 12% 12% 2	1900
	11th to 20th	Night	50% 4 10% 21% 12% 3	1712
	21st to end	Night	53% 5% 11% 15% 15% 1	1655
May	1st to 10th	Night	59% 8% 10% 16% 6%	2530
	11th to 20th	Night	44% 6% 14% 28% 7% 1	2507
	21st to end	Night	59% 6% 10% 16% 8% 1	2474
June	1st to 10th	Night	54% 7% 12% 19% 8% 1	1330
	11th to 20th	Night	48% 7% 16% 19% 8% 1	1330
	21st to end	Night	57% 6% 11% 18% 7%	1330
July	1st to 10th	Night	49% 7% 14% 19% 10%	2175
	11th to 20th	Night	50% 6% 14% 23% 7%	2168
	21st to end	Night	40% 6% 16% 29% 9%	2416
August	1st to 10th	Night	49% 6% 18% 22% 6%	2525
	11th to 20th	Night	51% 7% 19% 19% 5%	2809
	21st to end	Night	47% 5% 17% 21% 9%	3187
September	1st to 10th	Night	46% 6% 14% 23% 10% 1	1900
	11th to 20th	Night	49% 5% 16% 22% 8%	1924
	21st to end	Night	47% 6% 14% 22% 10% 1	2176
October	1st to 10th	Night	51% 4 11% 26% 6% 1	3800
	11th to 20th	Night	51% 4 14% 22% 8%	3779
	21st to end	Night	51% 4 10% 23% 12% 1	4486
November	1st to 10th	Night	55% 7% 12% 16% 9% 1	2733
	11th to 20th	Night	63% 6% 11% 13% 7%	2800
	21st to end	Night	64% 6% 11% 12% 7%	2800
December	1st to 10th	Night	62% 7% 10% 14% 6%	2870
	11th to 20th	Night	61% 8% 9% 14% 7% 1	3532
	21st to end	Night	51% 8% 14% 17% 9% 1	5236

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	18% 12% 27% 29% 14% 1	180
	11th to 20th	Day	26% 11% 28% 22% 12% 2	180
	21st to end	Day	17% 9% 31% 28% 12% 3	287
February	1st to 10th	Day	18% 10% 37% 23% 10% 2	370
	11th to 20th	Day	16% 8% 32% 27% 14% 1	366
	21st to end	Day	18% 6% 30% 28% 14% 4	307
March	1st to 10th	Day	17% 7% 30% 32% 12% 2	416
	11th to 20th	Day	23% 10% 23% 28% 13% 3	460
	21st to end	Day	24% 10% 26% 26% 12% 2	506
April	1st to 10th	Day	29% 10% 23% 28% 9%	460
	11th to 20th	Day	21% 9% 24% 28% 16% 3	452
	21st to end	Day	30% 6% 20% 28% 12% 4	514
May	1st to 10th	Day	29% 5% 20% 30% 13% 4	653
	11th to 20th	Day	23% 5% 26% 28% 15% 4	674
	21st to end	Day	27% 6% 24% 30% 12% 1	735
June	1st to 10th	Day	29% 3 18% 33% 16% 2	680
	11th to 20th	Day	27% 4 19% 26% 20% 4	680
	21st to end	Day	27% 4 20% 29% 17% 3	680
July	1st to 10th	Day	20% 4 17% 36% 20% 3	670
	11th to 20th	Day	21% 4 15% 35% 21% 3	668
	21st to end	Day	27% 4 15% 30% 21% 4	740
August	1st to 10th	Day	18% 3 13% 36% 23% 6%	665
	11th to 20th	Day	21% 2 17% 33% 23% 4	479
	21st to end	Day	19% 4 20% 32% 20% 5%	539
September	1st to 10th	Day	24% 6% 20% 33% 14% 2	490
	11th to 20th	Day	26% 8% 25% 26% 13% 2	490
	21st to end	Day	24% 5% 30% 28% 11% 1	443
October	1st to 10th	Day	23% 6% 31% 27% 12% 2	390
	11th to 20th	Day	29% 6% 31% 21% 12% 2	390
	21st to end	Day	30% 10% 26% 21% 10% 3	429
November	1st to 10th	Day	26% 12% 29% 27% 5% 1	395
	11th to 20th	Day	36% 9% 24% 21% 9% 2	400
	21st to end	Day	34% 12% 26% 21% 7% 1	400
December	1st to 10th	Day	24% 10% 26% 27% 11% 3	250
	11th to 20th	Day	21% 16% 36% 18% 7% 2	180
	21st to end	Day	19% 17% 33% 22% 9% 1	198
January	1st to 10th	Night	22% 9% 33% 26% 9% 1	850
	11th to 20th	Night	23% 11% 33% 25% 8% 1	850
	21st to end	Night	18% 11% 36% 26% 10% 1	920
February	1st to 10th	Night	15% 12% 34% 28% 10% 1	760
	11th to 20th	Night	20% 7% 33% 29% 9% 2	743
	21st to end	Night	16% 8% 30% 29% 13% 4	628
March	1st to 10th	Night	18% 9% 30% 30% 12% 1	760
	11th to 20th	Night	21% 7% 30% 29% 11% 1	760
	21st to end	Night	22% 8% 30% 30% 8% 2	796
April	1st to 10th	Night	29% 8% 26% 26% 12%	570
	11th to 20th	Night	24% 5% 26% 32% 10% 2	564
	21st to end	Night	25% 6% 22% 30% 14% 2	570
May	1st to 10th	Night	27% 3 16% 34% 16% 3	570
	11th to 20th	Night	23% 4 20% 30% 20% 3	562
	21st to end	Night	27% 4 20% 35% 13% 2	457
June	1st to 10th	Night	29% 3 14% 39% 13% 2	380
	11th to 20th	Night	27% 3 14% 30% 24% 3	380
	21st to end	Night	29% 3 13% 36% 17% 2	380
July	1st to 10th	Night	20% 3 12% 40% 22% 2	370
	11th to 20th	Night	20% 3 12% 45% 18% 2	368
	21st to end	Night	23% 2 12% 35% 25% 3	473
August	1st to 10th	Night	18% 3 16% 31% 27% 5%	568
	11th to 20th	Night	22% 3 12% 36% 24% 2	562
	21st to end	Night	19% 3 18% 34% 23% 4	627
September	1st to 10th	Night	25% 5% 21% 32% 14% 2	570
	11th to 20th	Night	26% 6% 21% 34% 12% 1	594
	21st to end	Night	26% 5% 25% 31% 12% 1	760
October	1st to 10th	Night	29% 5% 26% 28% 11% 1	760
	11th to 20th	Night	32% 6% 24% 25% 13% 1	760
	21st to end	Night	29% 7% 25% 26% 10% 1	906
November	1st to 10th	Night	28% 12% 32% 22% 5% 1	880
	11th to 20th	Night	33% 11% 26% 23% 6% 1	900
	21st to end	Night	31% 11% 28% 24% 6%	900
December	1st to 10th	Night	27% 10% 31% 24% 8% 1	878
	11th to 20th	Night	24% 15% 34% 20% 6% 1	850
	21st to end	Night	25% 13% 29% 23% 8% 2	935

Page generated at 2024-12-03 06:45:13. Version ac07

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