Natashquan
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Natashquan clear sky chart from 2005-11-06 to 2024-02-10.

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% 10% 4 6% 5% 3 4 4 5% 6% 33%	77705
	Night	19% 12% 4 7% 5% 3 4 4 5% 6% 31%	81249
Transparency	Day	51% 7% 13% 18% 9% 1	77398
	Night	54% 6% 12% 18% 9% 1	81092
Seeing	Day	25% 9% 26% 26% 12% 3	15932
	Night	25% 9% 28% 27% 10% 1	23289

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	10% 15% 7% 8% 5% 3 3 2 3 4 39%	2207
	11th to 20th	Day	14% 16% 5% 9% 7% 3 4 5% 7% 7% 24%	2210
	21st to end	Day	8% 9% 4 7% 6% 3 4 5% 5% 7% 41%	2781
February	1st to 10th	Day	12% 15% 5% 8% 6% 3 5% 4 4 6% 32%	1653
	11th to 20th	Day	12% 13% 5% 7% 8% 4 6% 3 5% 8% 29%	1573
	21st to end	Day	11% 11% 5% 7% 5% 2 5% 4 5% 5% 39%	1372
March	1st to 10th	Day	11% 11% 6% 8% 6% 4 5% 5% 4 6% 34%	1809
	11th to 20th	Day	16% 11% 4 6% 8% 4 4 4 5% 5% 33%	1980
	21st to end	Day	15% 13% 5% 8% 7% 2 4 3 4 6% 33%	2272
April	1st to 10th	Day	23% 12% 5% 8% 5% 3 5% 4 4 6% 26%	2160
	11th to 20th	Day	16% 10% 3 6% 6% 3 4 4 5% 6% 36%	2204
	21st to end	Day	25% 9% 3 5% 5% 2 3 4 4 6% 34%	2456
May	1st to 10th	Day	28% 9% 4 5% 5% 2 4 4 3 5% 30%	2520
	11th to 20th	Day	21% 9% 3 6% 6% 3 3 3 5% 6% 34%	2478
	21st to end	Day	24% 8% 3 6% 5% 3 4 4 4 6% 32%	2782
June	1st to 10th	Day	29% 9% 4 5% 5% 3 4 5% 6% 6% 26%	2700
	11th to 20th	Day	25% 6% 3 5% 5% 3 5% 4 5% 6% 33%	2700
	21st to end	Day	26% 8% 3 6% 5% 3 4 5% 5% 6% 29%	2700
July	1st to 10th	Day	18% 8% 3 6% 6% 3 4 5% 6% 8% 33%	2700
	11th to 20th	Day	19% 6% 2 5% 5% 3 4 5% 6% 8% 38%	2700
	21st to end	Day	24% 7% 3 5% 4 3 4 4 5% 7% 34%	2769
August	1st to 10th	Day	17% 7% 2 7% 5% 3 4 5% 7% 9% 35%	2506
	11th to 20th	Day	20% 7% 3 6% 5% 3 4 5% 6% 7% 34%	2377
	21st to end	Day	19% 6% 2 5% 5% 3 4 6% 5% 8% 37%	2476
September	1st to 10th	Day	22% 6% 2 5% 4 3 4 5% 5% 6% 38%	2160
	11th to 20th	Day	24% 8% 2 5% 4 3 3 4 4 5% 38%	2160
	21st to end	Day	21% 7% 2 5% 5% 3 4 5% 5% 8% 36%	1900
October	1st to 10th	Day	20% 7% 2 5% 5% 3 5% 4 5% 7% 38%	1800
	11th to 20th	Day	24% 9% 3 6% 6% 2 3 4 5% 6% 33%	1800
	21st to end	Day	23% 11% 3 5% 5% 3 4 4 4 6% 33%	1783
November	1st to 10th	Day	25% 10% 3 6% 5% 3 4 4 5% 6% 29%	1485
	11th to 20th	Day	24% 14% 4 5% 4 2 4 3 4 5% 30%	1520
	21st to end	Day	23% 15% 5% 5% 6% 2 3 4 3 4 29%	1520
December	1st to 10th	Day	21% 12% 5% 7% 5% 2 4 3 5% 6% 29%	1475
	11th to 20th	Day	21% 13% 6% 9% 6% 2 4 3 4 6% 26%	1586
	21st to end	Day	13% 12% 5% 7% 5% 3 5% 5% 6% 7% 30%	2431
January	1st to 10th	Night	11% 14% 6% 8% 5% 3 3 3 4 4 38%	4748
	11th to 20th	Night	18% 15% 6% 8% 6% 3 4 4 6% 6% 24%	4760
	21st to end	Night	8% 11% 6% 10% 7% 4 4 4 4 6% 36%	4884
February	1st to 10th	Night	10% 14% 5% 9% 7% 4 6% 4 6% 8% 28%	2509
	11th to 20th	Night	14% 13% 5% 8% 7% 3 5% 4 5% 6% 31%	2273
	21st to end	Night	9% 15% 5% 7% 5% 4 5% 5% 5% 6% 34%	1884
March	1st to 10th	Night	13% 13% 6% 7% 6% 3 4 4 6% 5% 32%	2133
	11th to 20th	Night	15% 12% 5% 7% 7% 3 6% 5% 5% 5% 31%	1979
	21st to end	Night	16% 16% 6% 7% 6% 3 4 3 4 5% 30%	2084
April	1st to 10th	Night	27% 11% 5% 6% 6% 3 4 4 4 5% 24%	1800
	11th to 20th	Night	18% 11% 3 6% 6% 3 4 4 3 5% 37%	1703
	21st to end	Night	22% 10% 4 6% 6% 3 4 4 4 4 32%	1503
May	1st to 10th	Night	26% 8% 3 5% 4 2 4 4 5% 5% 34%	1440
	11th to 20th	Night	22% 8% 2 6% 6% 3 4 5% 4 7% 34%	1416
	21st to end	Night	24% 8% 3 6% 6% 3 3 4 4 8% 31%	1506
June	1st to 10th	Night	30% 8% 3 5% 4 3 4 5% 5% 7% 26%	1260
	11th to 20th	Night	23% 5% 2 5% 5% 3 6% 6% 6% 7% 31%	1260
	21st to end	Night	27% 9% 3 7% 5% 3 4 3 3 8% 28%	1260
July	1st to 10th	Night	20% 7% 3 7% 5% 3 4 4 7% 8% 31%	1260
	11th to 20th	Night	20% 7% 2 4 5% 2 4 4 5% 7% 39%	1260
	21st to end	Night	23% 7% 3 6% 5% 3 4 5% 5% 8% 31%	1528
August	1st to 10th	Night	19% 6% 3 5% 5% 3 5% 5% 6% 8% 35%	1433
	11th to 20th	Night	21% 6% 2 6% 6% 3 4 4 6% 8% 33%	1521
	21st to end	Night	18% 6% 3 6% 7% 4 5% 4 6% 8% 34%	1879
September	1st to 10th	Night	23% 7% 3 5% 4 3 4 3 5% 6% 38%	1800
	11th to 20th	Night	23% 6% 2 5% 4 3 4 4 4 7% 38%	1800
	21st to end	Night	27% 6% 2 4 4 2 3 4 5% 7% 37%	2057
October	1st to 10th	Night	21% 9% 3 6% 5% 3 4 3 4 6% 35%	2160
	11th to 20th	Night	26% 9% 3 6% 6% 3 4 4 4 6% 31%	2160
	21st to end	Night	23% 10% 3 6% 4 3 5% 4 5% 6% 32%	2568
November	1st to 10th	Night	23% 10% 3 6% 5% 4 3 5% 5% 6% 30%	2593
	11th to 20th	Night	25% 15% 4 6% 5% 3 4 3 4 5% 25%	2660
	21st to end	Night	21% 16% 6% 7% 5% 3 3 4 4 5% 27%	2660
December	1st to 10th	Night	19% 16% 6% 8% 5% 3 4 3 4 7% 25%	2679
	11th to 20th	Night	24% 13% 6% 8% 6% 3 4 3 4 6% 24%	3593
	21st to end	Night	13% 17% 6% 8% 5% 3 4 4 4 7% 31%	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	51% 4 10% 12% 18% 5%	2208
	11th to 20th	Day	57% 8% 16% 14% 5%	2210
	21st to end	Day	40% 11% 17% 14% 13% 5%	2781
February	1st to 10th	Day	54% 6% 11% 18% 10% 1	1653
	11th to 20th	Day	55% 6% 10% 18% 10%	1581
	21st to end	Day	47% 6% 10% 22% 15% 1	1372
March	1st to 10th	Day	51% 5% 12% 19% 12% 1	1813
	11th to 20th	Day	53% 6% 9% 18% 14% 1	1980
	21st to end	Day	54% 4 11% 17% 12% 2	2272
April	1st to 10th	Day	59% 6% 9% 12% 12% 1	2160
	11th to 20th	Day	48% 7% 10% 21% 12% 2	2204
	21st to end	Day	52% 5% 12% 18% 12% 1	2456
May	1st to 10th	Day	55% 7% 10% 19% 8%	2520
	11th to 20th	Day	50% 7% 12% 18% 11% 1	2482
	21st to end	Day	53% 6% 12% 19% 9% 1	2782
June	1st to 10th	Day	58% 8% 12% 15% 7% 1	2700
	11th to 20th	Day	53% 7% 10% 22% 8%	2700
	21st to end	Day	54% 8% 12% 17% 8%	2700
July	1st to 10th	Day	47% 9% 18% 19% 7%	2625
	11th to 20th	Day	44% 7% 17% 23% 8%	2619
	21st to end	Day	49% 8% 16% 20% 7%	2614
August	1st to 10th	Day	44% 10% 23% 18% 5%	2492
	11th to 20th	Day	47% 10% 16% 20% 6% 1	2377
	21st to end	Day	44% 10% 19% 23% 4	2476
September	1st to 10th	Day	46% 8% 14% 24% 8%	2160
	11th to 20th	Day	48% 6% 14% 23% 8% 1	2160
	21st to end	Day	46% 7% 15% 21% 10% 1	1900
October	1st to 10th	Day	45% 8% 14% 24% 8% 1	1800
	11th to 20th	Day	52% 7% 13% 22% 6%	1800
	21st to end	Day	54% 6% 13% 17% 9% 1	1783
November	1st to 10th	Day	56% 7% 13% 15% 9%	1485
	11th to 20th	Day	58% 6% 11% 17% 8%	1520
	21st to end	Day	60% 5% 11% 17% 8%	1520
December	1st to 10th	Day	57% 7% 13% 16% 6%	1475
	11th to 20th	Day	62% 5% 11% 15% 6%	1587
	21st to end	Day	52% 8% 14% 15% 9% 1	2431
January	1st to 10th	Night	51% 4 10% 17% 16% 3	4748
	11th to 20th	Night	59% 6% 15% 14% 7%	4760
	21st to end	Night	48% 6% 12% 15% 17% 1	4884
February	1st to 10th	Night	54% 5% 12% 18% 8% 2	2509
	11th to 20th	Night	55% 5% 11% 18% 9% 1	2276
	21st to end	Night	51% 5% 10% 19% 12% 3	1884
March	1st to 10th	Night	51% 6% 10% 18% 13% 2	2142
	11th to 20th	Night	54% 5% 9% 17% 13% 2	1980
	21st to end	Night	58% 4 9% 15% 11% 3	2084
April	1st to 10th	Night	62% 6% 7% 12% 11% 2	1800
	11th to 20th	Night	51% 5% 9% 22% 12% 2	1703
	21st to end	Night	56% 4 11% 13% 14% 1	1503
May	1st to 10th	Night	52% 7% 11% 19% 10% 1	1440
	11th to 20th	Night	49% 6% 12% 24% 9% 1	1417
	21st to end	Night	53% 6% 13% 17% 10% 1	1507
June	1st to 10th	Night	57% 7% 11% 17% 8%	1260
	11th to 20th	Night	49% 9% 13% 23% 6%	1260
	21st to end	Night	57% 7% 11% 20% 5%	1260
July	1st to 10th	Night	50% 7% 15% 22% 6%	1225
	11th to 20th	Night	43% 9% 14% 26% 8%	1218
	21st to end	Night	51% 9% 15% 20% 5%	1443
August	1st to 10th	Night	45% 10% 19% 20% 5%	1422
	11th to 20th	Night	48% 10% 16% 19% 6%	1521
	21st to end	Night	47% 9% 17% 23% 4	1879
September	1st to 10th	Night	47% 7% 15% 21% 10%	1800
	11th to 20th	Night	46% 7% 15% 24% 8%	1800
	21st to end	Night	46% 7% 16% 20% 10% 1	2057
October	1st to 10th	Night	51% 6% 12% 19% 10% 2	2160
	11th to 20th	Night	54% 5% 13% 20% 7%	2160
	21st to end	Night	53% 6% 12% 20% 8% 2	2568
November	1st to 10th	Night	55% 7% 13% 15% 8% 1	2593
	11th to 20th	Night	62% 6% 11% 15% 6%	2660
	21st to end	Night	61% 6% 12% 15% 6%	2660
December	1st to 10th	Night	61% 6% 14% 13% 6%	2679
	11th to 20th	Night	63% 4 11% 15% 6%	3594
	21st to end	Night	55% 6% 14% 17% 8% 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	17% 14% 34% 20% 12% 2	180
	11th to 20th	Day	27% 14% 20% 27% 12% 1	180
	21st to end	Day	17% 11% 33% 25% 11% 2	405
February	1st to 10th	Day	19% 12% 36% 23% 8% 2	367
	11th to 20th	Day	19% 11% 36% 24% 9% 2	336
	21st to end	Day	19% 8% 32% 24% 14% 3	280
March	1st to 10th	Day	17% 11% 31% 28% 10% 3	346
	11th to 20th	Day	23% 10% 26% 23% 14% 4	420
	21st to end	Day	23% 13% 30% 23% 8% 4	462
April	1st to 10th	Day	28% 12% 28% 24% 6% 1	420
	11th to 20th	Day	20% 10% 31% 24% 12% 3	412
	21st to end	Day	28% 7% 26% 24% 13% 2	536
May	1st to 10th	Day	30% 8% 22% 25% 12% 3	603
	11th to 20th	Day	25% 8% 25% 25% 14% 4	624
	21st to end	Day	27% 7% 28% 28% 8% 2	680
June	1st to 10th	Day	33% 5% 25% 26% 11% 1	630
	11th to 20th	Day	29% 6% 20% 27% 17% 2	630
	21st to end	Day	28% 8% 20% 26% 15% 3	630
July	1st to 10th	Day	24% 4 23% 29% 17% 3	620
	11th to 20th	Day	23% 4 18% 34% 19% 2	618
	21st to end	Day	27% 4 17% 32% 17% 3	685
August	1st to 10th	Day	21% 4 15% 35% 20% 5%	625
	11th to 20th	Day	22% 4 18% 32% 19% 4	512
	21st to end	Day	21% 6% 23% 29% 17% 4	495
September	1st to 10th	Day	23% 8% 28% 25% 13% 2	450
	11th to 20th	Day	29% 10% 26% 26% 8% 2	450
	21st to end	Day	25% 8% 31% 23% 10% 2	381
October	1st to 10th	Day	25% 8% 34% 23% 8% 2	360
	11th to 20th	Day	28% 8% 31% 20% 11% 3	360
	21st to end	Day	28% 12% 25% 20% 13% 2	396
November	1st to 10th	Day	27% 17% 26% 22% 6% 1	365
	11th to 20th	Day	31% 13% 26% 21% 7% 2	370
	21st to end	Day	31% 12% 27% 24% 6%	370
December	1st to 10th	Day	26% 10% 30% 23% 8% 3	356
	11th to 20th	Day	25% 18% 31% 19% 7%	180
	21st to end	Day	20% 18% 33% 20% 8% 2	198
January	1st to 10th	Night	23% 11% 32% 26% 7% 1	850
	11th to 20th	Night	25% 14% 32% 24% 6%	850
	21st to end	Night	18% 13% 36% 24% 7% 1	935
February	1st to 10th	Night	18% 12% 33% 27% 10%	780
	11th to 20th	Night	21% 8% 40% 24% 7% 1	703
	21st to end	Night	16% 8% 30% 27% 17% 2	592
March	1st to 10th	Night	18% 11% 33% 28% 9% 1	720
	11th to 20th	Night	19% 9% 33% 28% 9% 1	720
	21st to end	Night	24% 13% 31% 23% 8% 1	698
April	1st to 10th	Night	31% 10% 25% 22% 11%	540
	11th to 20th	Night	24% 6% 31% 26% 10% 2	534
	21st to end	Night	26% 5% 24% 29% 14% 2	540
May	1st to 10th	Night	30% 6% 19% 28% 13% 3	540
	11th to 20th	Night	26% 3 23% 32% 14% 2	532
	21st to end	Night	27% 6% 27% 29% 11% 1	539
June	1st to 10th	Night	35% 3 20% 31% 10% 1	360
	11th to 20th	Night	24% 3 20% 33% 18% 1	360
	21st to end	Night	31% 6% 14% 34% 13% 3	360
July	1st to 10th	Night	23% 2 17% 36% 20% 2	350
	11th to 20th	Night	22% 2 21% 39% 16% 1	348
	21st to end	Night	26% 3 16% 36% 17% 3	545
August	1st to 10th	Night	22% 2 16% 35% 22% 3	538
	11th to 20th	Night	22% 2 20% 33% 20% 3	532
	21st to end	Night	20% 3 22% 37% 16% 3	594
September	1st to 10th	Night	26% 5% 24% 30% 14% 1	540
	11th to 20th	Night	26% 7% 26% 32% 9%	540
	21st to end	Night	30% 7% 26% 28% 10%	658
October	1st to 10th	Night	27% 7% 31% 28% 7% 1	720
	11th to 20th	Night	31% 7% 26% 23% 12% 1	720
	21st to end	Night	27% 10% 25% 28% 9%	886
November	1st to 10th	Night	28% 14% 30% 22% 6% 1	830
	11th to 20th	Night	32% 12% 28% 20% 7% 1	850
	21st to end	Night	28% 12% 31% 24% 4	850
December	1st to 10th	Night	27% 11% 34% 21% 7%	850
	11th to 20th	Night	25% 17% 34% 18% 6% 1	850
	21st to end	Night	24% 14% 31% 23% 6% 1	935

Page generated at 2024-02-07 06:11:56. Version ac07

Copyright 2024 Attilla Danko