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 2024-01-16.

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	20% 9% 4 6% 5% 3 4 4 5% 6% 33%	74707
	Night	20% 11% 4 7% 5% 3 4 4 5% 6% 31%	75099
Transparency	Day	51% 7% 14% 19% 9% 1	74394
	Night	54% 7% 12% 17% 9% 1	74947
Seeing	Day	25% 6% 23% 29% 15% 3	15546
	Night	25% 7% 26% 29% 12% 2	23046

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	15% 15% 7% 8% 6% 3 4 3 4 5% 29%	1327
	11th to 20th	Day	15% 15% 7% 9% 6% 3 4 4 5% 7% 25%	1295
	21st to end	Day	12% 13% 5% 7% 7% 3 5% 4 6% 8% 29%	1498
February	1st to 10th	Day	10% 12% 5% 9% 7% 3 7% 4 5% 6% 32%	1620
	11th to 20th	Day	11% 13% 5% 9% 7% 4 5% 4 4 7% 30%	1573
	21st to end	Day	10% 12% 6% 7% 5% 4 6% 5% 4 5% 37%	1332
March	1st to 10th	Day	10% 14% 7% 8% 5% 3 4 5% 4 6% 34%	1864
	11th to 20th	Day	16% 12% 4 6% 6% 4 5% 4 4 6% 33%	1980
	21st to end	Day	14% 14% 4 7% 5% 3 4 4 5% 5% 35%	2214
April	1st to 10th	Day	23% 13% 4 7% 5% 3 4 4 4 6% 28%	2160
	11th to 20th	Day	15% 10% 3 5% 5% 3 4 5% 4 6% 39%	2285
	21st to end	Day	24% 9% 3 4 4 2 3 3 4 5% 37%	2391
May	1st to 10th	Day	25% 8% 3 6% 6% 3 4 4 4 6% 31%	2520
	11th to 20th	Day	21% 8% 4 6% 5% 3 4 4 5% 7% 33%	2478
	21st to end	Day	24% 7% 3 6% 5% 3 4 4 5% 7% 32%	2890
June	1st to 10th	Day	26% 8% 3 5% 5% 3 4 4 5% 6% 30%	2700
	11th to 20th	Day	23% 6% 2 4 5% 3 4 5% 6% 8% 34%	2700
	21st to end	Day	24% 7% 3 6% 5% 3 5% 4 5% 7% 32%	2700
July	1st to 10th	Day	18% 7% 3 6% 5% 3 5% 4 7% 8% 34%	2700
	11th to 20th	Day	18% 5% 2 5% 5% 4 4 6% 7% 8% 37%	2700
	21st to end	Day	24% 6% 3 6% 5% 3 5% 4 6% 7% 32%	2869
August	1st to 10th	Day	15% 6% 2 5% 6% 3 5% 6% 7% 9% 35%	2497
	11th to 20th	Day	21% 8% 3 5% 5% 3 4 4 5% 7% 35%	2304
	21st to end	Day	20% 5% 2 5% 5% 3 5% 4 6% 7% 37%	2538
September	1st to 10th	Day	21% 5% 2 5% 4 3 5% 5% 5% 6% 39%	2160
	11th to 20th	Day	25% 7% 3 5% 4 2 3 4 4 5% 39%	2134
	21st to end	Day	22% 5% 2 5% 5% 2 4 5% 4 5% 39%	1898
October	1st to 10th	Day	18% 6% 2 5% 5% 3 4 5% 5% 6% 40%	1800
	11th to 20th	Day	25% 7% 2 6% 3 3 4 5% 5% 7% 33%	1800
	21st to end	Day	25% 11% 3 6% 6% 2 3 3 4 5% 32%	1769
November	1st to 10th	Day	22% 10% 4 7% 5% 4 4 4 4 6% 31%	1485
	11th to 20th	Day	23% 14% 3 6% 4 3 4 4 4 6% 29%	1520
	21st to end	Day	23% 15% 5% 7% 6% 3 3 4 3 4 29%	1520
December	1st to 10th	Day	19% 14% 5% 7% 6% 4 4 4 4 5% 27%	1387
	11th to 20th	Day	19% 12% 6% 7% 6% 4 6% 4 4 6% 26%	1668
	21st to end	Day	12% 13% 5% 7% 5% 4 4 4 4 6% 36%	2431
January	1st to 10th	Night	15% 16% 6% 9% 7% 3 4 3 5% 6% 28%	2838
	11th to 20th	Night	16% 14% 6% 8% 7% 2 4 4 4 8% 26%	2787
	21st to end	Night	11% 13% 6% 8% 8% 4 5% 4 5% 8% 28%	2854
February	1st to 10th	Night	9% 14% 6% 9% 6% 3 6% 4 5% 7% 31%	2340
	11th to 20th	Night	12% 15% 6% 7% 6% 3 5% 5% 5% 5% 30%	2273
	21st to end	Night	10% 14% 6% 8% 7% 4 6% 5% 4 6% 31%	1924
March	1st to 10th	Night	13% 13% 6% 8% 5% 3 4 3 4 5% 36%	2078
	11th to 20th	Night	14% 13% 4 6% 6% 4 5% 5% 5% 5% 32%	1979
	21st to end	Night	16% 15% 5% 8% 5% 3 4 4 4 4 33%	2141
April	1st to 10th	Night	24% 12% 4 8% 6% 3 5% 4 5% 5% 25%	1800
	11th to 20th	Night	18% 11% 4 5% 5% 4 4 4 4 5% 38%	1621
	21st to end	Night	24% 9% 4 6% 5% 2 4 5% 4 5% 33%	1568
May	1st to 10th	Night	25% 9% 3 5% 5% 3 3 4 5% 7% 31%	1440
	11th to 20th	Night	21% 8% 4 7% 4 3 4 4 4 5% 35%	1416
	21st to end	Night	24% 7% 3 6% 5% 3 5% 4 5% 6% 33%	1400
June	1st to 10th	Night	28% 6% 3 5% 5% 3 5% 5% 5% 7% 28%	1260
	11th to 20th	Night	24% 7% 3 4 5% 3 5% 4 5% 8% 32%	1260
	21st to end	Night	27% 7% 4 6% 7% 3 5% 5% 4 5% 27%	1260
July	1st to 10th	Night	18% 7% 4 6% 6% 3 6% 5% 5% 9% 30%	1260
	11th to 20th	Night	20% 5% 4 5% 4 3 4 5% 6% 7% 37%	1260
	21st to end	Night	22% 7% 3 5% 6% 3 5% 6% 6% 8% 29%	1431
August	1st to 10th	Night	19% 7% 2 6% 5% 3 5% 5% 5% 8% 35%	1440
	11th to 20th	Night	23% 7% 3 5% 4 3 5% 4 5% 6% 35%	1596
	21st to end	Night	18% 8% 3 7% 5% 4 6% 5% 6% 7% 32%	1818
September	1st to 10th	Night	23% 6% 2 4 4 3 3 4 5% 6% 40%	1800
	11th to 20th	Night	24% 6% 2 6% 5% 3 4 3 4 6% 37%	1822
	21st to end	Night	25% 6% 2 4 4 3 4 4 4 7% 37%	2061
October	1st to 10th	Night	24% 8% 3 6% 5% 3 4 3 4 5% 35%	2160
	11th to 20th	Night	29% 7% 3 5% 5% 3 4 5% 4 4 31%	2160
	21st to end	Night	26% 9% 3 6% 5% 2 3 4 4 6% 32%	2581
November	1st to 10th	Night	25% 10% 3 6% 5% 3 4 5% 4 5% 30%	2593
	11th to 20th	Night	25% 13% 5% 7% 5% 3 4 4 4 5% 26%	2660
	21st to end	Night	24% 16% 5% 6% 5% 2 4 3 4 5% 26%	2660
December	1st to 10th	Night	20% 14% 6% 7% 6% 3 4 4 4 6% 26%	2791
	11th to 20th	Night	24% 12% 5% 7% 5% 3 3 4 4 6% 27%	3531
	21st to end	Night	13% 14% 4 6% 5% 3 4 4 5% 6% 34%	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	60% 8% 10% 13% 8% 1	1328
	11th to 20th	Day	61% 9% 9% 13% 7% 1	1295
	21st to end	Day	54% 11% 10% 16% 9% 1	1498
February	1st to 10th	Day	53% 7% 10% 17% 10% 1	1620
	11th to 20th	Day	56% 6% 10% 18% 9%	1581
	21st to end	Day	51% 6% 10% 21% 12% 1	1332
March	1st to 10th	Day	51% 6% 11% 19% 11% 2	1868
	11th to 20th	Day	52% 5% 8% 19% 14% 2	1980
	21st to end	Day	51% 5% 12% 17% 12% 3	2214
April	1st to 10th	Day	58% 5% 11% 13% 11% 2	2160
	11th to 20th	Day	47% 5% 11% 22% 13% 2	2285
	21st to end	Day	51% 4 14% 18% 13% 1	2391
May	1st to 10th	Day	54% 4 11% 21% 9% 1	2520
	11th to 20th	Day	49% 6% 14% 19% 11% 1	2482
	21st to end	Day	52% 5% 12% 19% 10% 1	2890
June	1st to 10th	Day	56% 5% 12% 17% 9% 1	2700
	11th to 20th	Day	48% 7% 14% 22% 9% 1	2700
	21st to end	Day	51% 8% 13% 19% 8%	2700
July	1st to 10th	Day	48% 8% 17% 18% 8%	2625
	11th to 20th	Day	42% 9% 16% 24% 8%	2619
	21st to end	Day	52% 7% 15% 20% 6%	2709
August	1st to 10th	Day	42% 10% 27% 16% 4	2483
	11th to 20th	Day	47% 7% 19% 19% 7% 1	2304
	21st to end	Day	45% 7% 21% 23% 4	2538
September	1st to 10th	Day	45% 6% 16% 23% 9%	2160
	11th to 20th	Day	47% 6% 16% 22% 8%	2134
	21st to end	Day	46% 7% 15% 22% 10%	1898
October	1st to 10th	Day	44% 6% 19% 22% 8% 1	1800
	11th to 20th	Day	51% 6% 14% 22% 7%	1800
	21st to end	Day	56% 5% 12% 18% 8% 1	1769
November	1st to 10th	Day	56% 7% 12% 15% 10%	1485
	11th to 20th	Day	60% 6% 10% 16% 7%	1520
	21st to end	Day	61% 7% 9% 16% 7%	1520
December	1st to 10th	Day	59% 9% 11% 16% 4 1	1387
	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	60% 8% 10% 14% 7%	2838
	11th to 20th	Night	59% 11% 9% 13% 7% 1	2787
	21st to end	Night	55% 10% 9% 16% 9% 1	2854
February	1st to 10th	Night	54% 9% 9% 16% 10% 2	2340
	11th to 20th	Night	55% 6% 11% 17% 10% 1	2276
	21st to end	Night	55% 6% 9% 17% 11% 2	1924
March	1st to 10th	Night	51% 6% 8% 19% 14% 2	2087
	11th to 20th	Night	53% 6% 10% 16% 14% 1	1980
	21st to end	Night	55% 5% 9% 18% 9% 5%	2141
April	1st to 10th	Night	62% 4 8% 12% 11% 2	1800
	11th to 20th	Night	50% 4 10% 20% 12% 3	1621
	21st to end	Night	53% 5% 11% 15% 16%	1568
May	1st to 10th	Night	53% 5% 12% 19% 10% 1	1440
	11th to 20th	Night	51% 5% 11% 22% 10% 1	1417
	21st to end	Night	53% 5% 10% 19% 12% 1	1401
June	1st to 10th	Night	55% 7% 12% 18% 7% 1	1260
	11th to 20th	Night	49% 7% 15% 19% 8% 1	1260
	21st to end	Night	58% 6% 11% 17% 7%	1260
July	1st to 10th	Night	47% 10% 18% 19% 6%	1225
	11th to 20th	Night	44% 7% 13% 27% 8%	1218
	21st to end	Night	50% 9% 15% 20% 6%	1351
August	1st to 10th	Night	48% 8% 21% 18% 5%	1429
	11th to 20th	Night	48% 8% 19% 19% 6%	1596
	21st to end	Night	50% 7% 17% 22% 4	1818
September	1st to 10th	Night	47% 6% 14% 23% 11% 1	1800
	11th to 20th	Night	49% 5% 15% 22% 8%	1822
	21st to end	Night	47% 6% 14% 22% 11% 1	2061
October	1st to 10th	Night	52% 5% 10% 22% 10% 2	2160
	11th to 20th	Night	56% 4 12% 19% 8%	2160
	21st to end	Night	55% 5% 11% 19% 8% 1	2581
November	1st to 10th	Night	56% 7% 12% 14% 9% 1	2593
	11th to 20th	Night	62% 7% 11% 13% 6%	2660
	21st to end	Night	63% 7% 11% 12% 7%	2660
December	1st to 10th	Night	62% 8% 10% 14% 6%	2791
	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% 10% 27% 22% 12% 2	170
	21st to end	Day	18% 8% 30% 30% 12% 2	261
February	1st to 10th	Day	19% 10% 39% 23% 8% 1	340
	11th to 20th	Day	18% 9% 33% 26% 13% 1	336
	21st to end	Day	17% 6% 30% 29% 15% 4	280
March	1st to 10th	Day	18% 8% 29% 31% 12% 2	380
	11th to 20th	Day	22% 10% 23% 29% 13% 4	420
	21st to end	Day	23% 8% 27% 27% 13% 2	462
April	1st to 10th	Day	31% 10% 24% 27% 9%	420
	11th to 20th	Day	21% 8% 25% 29% 15% 2	412
	21st to end	Day	29% 5% 20% 28% 13% 4	471
May	1st to 10th	Day	29% 5% 20% 31% 12% 4	603
	11th to 20th	Day	24% 5% 26% 26% 15% 4	624
	21st to end	Day	26% 5% 24% 31% 12% 1	680
June	1st to 10th	Day	30% 3 18% 33% 14% 1	630
	11th to 20th	Day	29% 4 17% 27% 20% 4	630
	21st to end	Day	27% 4 19% 29% 17% 3	630
July	1st to 10th	Day	20% 5% 17% 36% 19% 3	620
	11th to 20th	Day	22% 4 14% 35% 22% 3	618
	21st to end	Day	28% 3 13% 30% 22% 4	685
August	1st to 10th	Day	18% 3 12% 37% 24% 6%	616
	11th to 20th	Day	20% 2 16% 34% 23% 4	439
	21st to end	Day	20% 4 19% 32% 20% 5%	495
September	1st to 10th	Day	25% 5% 20% 32% 15% 3	450
	11th to 20th	Day	28% 8% 24% 25% 12% 2	450
	21st to end	Day	25% 5% 31% 28% 10%	408
October	1st to 10th	Day	21% 6% 33% 28% 11% 2	360
	11th to 20th	Day	29% 6% 29% 21% 12% 2	360
	21st to end	Day	32% 10% 24% 20% 11% 3	396
November	1st to 10th	Day	26% 12% 29% 26% 5% 1	365
	11th to 20th	Day	34% 10% 24% 22% 9% 2	370
	21st to end	Day	32% 11% 27% 21% 7% 1	370
December	1st to 10th	Day	24% 9% 26% 27% 11% 3	237
	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% 32% 26% 8% 1	829
	21st to end	Night	18% 10% 35% 26% 9% 1	866
February	1st to 10th	Night	16% 11% 35% 28% 9% 1	720
	11th to 20th	Night	21% 7% 32% 30% 9% 2	703
	21st to end	Night	16% 8% 30% 28% 14% 4	592
March	1st to 10th	Night	19% 8% 30% 29% 13% 1	720
	11th to 20th	Night	21% 7% 31% 29% 11% 1	720
	21st to end	Night	22% 8% 30% 30% 8% 2	755
April	1st to 10th	Night	30% 8% 26% 25% 11%	540
	11th to 20th	Night	23% 6% 26% 32% 10% 3	534
	21st to end	Night	26% 5% 23% 30% 14% 2	540
May	1st to 10th	Night	27% 3 16% 34% 16% 4	540
	11th to 20th	Night	24% 4 20% 30% 19% 2	532
	21st to end	Night	27% 3 20% 35% 13% 2	433
June	1st to 10th	Night	30% 3 14% 38% 13% 2	360
	11th to 20th	Night	27% 3 12% 31% 25% 3	360
	21st to end	Night	29% 4 13% 35% 18% 2	360
July	1st to 10th	Night	21% 3 11% 40% 23% 3	350
	11th to 20th	Night	20% 3 11% 46% 18% 2	348
	21st to end	Night	24% 2 11% 35% 25% 2	448
August	1st to 10th	Night	19% 3 15% 31% 28% 5%	538
	11th to 20th	Night	22% 2 12% 36% 25% 2	532
	21st to end	Night	19% 3 18% 35% 22% 3	594
September	1st to 10th	Night	25% 5% 22% 32% 15% 2	540
	11th to 20th	Night	27% 6% 21% 33% 12% 1	562
	21st to end	Night	26% 5% 26% 31% 11% 1	720
October	1st to 10th	Night	29% 5% 27% 27% 10% 1	720
	11th to 20th	Night	32% 5% 24% 25% 13% 1	720
	21st to end	Night	30% 7% 25% 26% 11% 1	855
November	1st to 10th	Night	29% 12% 32% 20% 6% 1	830
	11th to 20th	Night	32% 10% 26% 24% 6% 1	850
	21st to end	Night	30% 11% 28% 24% 6%	850
December	1st to 10th	Night	27% 10% 31% 24% 7% 1	850
	11th to 20th	Night	24% 15% 34% 20% 6% 1	850
	21st to end	Night	25% 13% 29% 23% 8% 2	935

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