Gros Morne National Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Gros Morne National Park clear sky chart from 2005-11-06 to 2026-02-01.

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% 16% 6% 12% 6% 5% 4 3 4 5% 19%	127762
	Night	18% 17% 7% 16% 8% 6% 4 2 3 4 14%	124516
Transparency	Day	69% 4 9% 13% 4	131167
	Night	76% 4 7% 10% 3	129218
Seeing	Day	33% 20% 25% 15% 6% 1	19692
	Night	33% 19% 23% 18% 6% 1	26804

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	7% 23% 10% 20% 15% 9% 3 2 2 2 5%	3534
	11th to 20th	Day	8% 17% 11% 33% 11% 7% 3 2 2 2 4	3671
	21st to end	Day	4 11% 7% 23% 18% 19% 7% 2 2 2 6%	4070
February	1st to 10th	Day	12% 17% 7% 18% 19% 10% 6% 2 2 3 4	1600
	11th to 20th	Day	10% 21% 9% 21% 11% 9% 5% 3 2 2 7%	1789
	21st to end	Day	10% 18% 7% 18% 10% 9% 7% 4 3 3 11%	1650
March	1st to 10th	Day	10% 18% 6% 16% 10% 11% 7% 3 3 3 13%	4474
	11th to 20th	Day	15% 24% 9% 14% 6% 6% 4 2 3 4 11%	4646
	21st to end	Day	19% 19% 8% 16% 6% 5% 3 2 3 3 15%	5971
April	1st to 10th	Day	17% 20% 9% 17% 9% 3 4 2 4 4 12%	2400
	11th to 20th	Day	16% 16% 7% 11% 5% 4 4 4 4 6% 23%	2459
	21st to end	Day	20% 17% 5% 10% 5% 4 3 3 4 5% 23%	2654
May	1st to 10th	Day	21% 21% 6% 9% 4 4 3 3 4 5% 20%	6345
	11th to 20th	Day	15% 15% 4 9% 4 4 5% 4 5% 7% 27%	6318
	21st to end	Day	23% 17% 3 9% 4 3 4 3 4 6% 23%	7294
June	1st to 10th	Day	27% 15% 4 8% 5% 4 4 4 4 7% 17%	3000
	11th to 20th	Day	24% 12% 3 6% 5% 4 5% 3 5% 6% 26%	3000
	21st to end	Day	27% 13% 3 6% 4 4 4 3 5% 5% 26%	3000
July	1st to 10th	Day	25% 12% 3 7% 4 4 5% 4 6% 6% 25%	6800
	11th to 20th	Day	26% 11% 3 8% 5% 4 4 3 5% 6% 25%	6363
	21st to end	Day	29% 10% 3 6% 4 4 4 3 5% 6% 26%	6927
August	1st to 10th	Day	27% 10% 3 7% 4 4 4 4 6% 7% 26%	4564
	11th to 20th	Day	25% 10% 3 6% 3 3 3 3 5% 6% 33%	4383
	21st to end	Day	30% 8% 2 6% 4 3 3 3 4 6% 30%	4454
September	1st to 10th	Day	28% 9% 3 6% 4 4 4 4 4 7% 27%	2400
	11th to 20th	Day	35% 12% 3 6% 4 3 4 3 5% 6% 20%	2295
	21st to end	Day	29% 14% 4 7% 4 4 3 3 5% 6% 21%	2200
October	1st to 10th	Day	25% 19% 3 6% 4 3 4 3 4 5% 23%	2081
	11th to 20th	Day	28% 23% 3 7% 3 3 5% 3 4 5% 16%	1855
	21st to end	Day	26% 27% 7% 8% 3 2 2 2 3 4 16%	1980
November	1st to 10th	Day	26% 31% 10% 10% 3 3 3 2 2 3 8%	1850
	11th to 20th	Day	22% 28% 9% 14% 4 2 2 3 3 3 11%	1632
	21st to end	Day	18% 29% 11% 18% 5% 2 2 2 3 3 8%	1470
December	1st to 10th	Day	11% 20% 16% 26% 10% 3 3 2 3 3 4	2360
	11th to 20th	Day	16% 22% 16% 22% 11% 4 1 2 2 2 4	2698
	21st to end	Day	13% 20% 9% 23% 11% 7% 2 2 3 3 7%	3575
January	1st to 10th	Night	6% 24% 11% 20% 13% 11% 4 2 2 2 3	6646
	11th to 20th	Night	10% 17% 9% 31% 9% 8% 4 2 2 2 6%	6454
	21st to end	Night	4 10% 6% 28% 17% 12% 10% 3 2 1 6%	7150
February	1st to 10th	Night	12% 17% 7% 21% 17% 12% 5% 1 1 1 5%	2801
	11th to 20th	Night	12% 19% 9% 21% 13% 9% 5% 3 2 3 5%	2495
	21st to end	Night	8% 17% 6% 19% 14% 9% 5% 4 4 3 11%	1980
March	1st to 10th	Night	8% 17% 8% 19% 12% 10% 4 3 3 4 12%	5366
	11th to 20th	Night	14% 20% 9% 17% 10% 7% 4 2 2 3 11%	5311
	21st to end	Night	17% 18% 9% 18% 8% 5% 4 2 3 4 12%	4961
April	1st to 10th	Night	19% 21% 9% 17% 6% 3 3 2 3 4 13%	2000
	11th to 20th	Night	14% 20% 7% 13% 5% 4 4 4 5% 4 21%	1890
	21st to end	Night	18% 16% 6% 10% 6% 4 4 3 5% 5% 22%	1744
May	1st to 10th	Night	23% 21% 6% 10% 4 3 3 2 5% 5% 18%	3615
	11th to 20th	Night	15% 16% 4 9% 5% 3 4 4 5% 7% 28%	3596
	21st to end	Night	24% 13% 4 9% 4 4 4 3 5% 6% 25%	3598
June	1st to 10th	Night	24% 13% 3 11% 6% 5% 5% 3 5% 6% 20%	1400
	11th to 20th	Night	22% 11% 5% 7% 4 4 4 3 6% 6% 28%	1400
	21st to end	Night	28% 11% 3 8% 4 3 4 4 5% 6% 24%	1400
July	1st to 10th	Night	31% 13% 4 8% 4 4 4 3 5% 6% 19%	3179
	11th to 20th	Night	26% 10% 3 8% 5% 4 4 3 5% 6% 26%	3613
	21st to end	Night	31% 9% 3 8% 4 4 3 3 4 5% 25%	3948
August	1st to 10th	Night	25% 11% 4 10% 5% 5% 4 4 5% 6% 21%	2596
	11th to 20th	Night	29% 10% 3 8% 4 4 3 3 5% 4 28%	2673
	21st to end	Night	29% 8% 2 6% 3 4 3 3 5% 6% 30%	3446
September	1st to 10th	Night	30% 9% 2 7% 5% 4 4 3 4 6% 25%	2000
	11th to 20th	Night	34% 12% 4 7% 4 3 3 3 4 5% 21%	2105
	21st to end	Night	35% 13% 2 7% 3 4 4 3 5% 6% 19%	2200
October	1st to 10th	Night	26% 18% 4 7% 4 4 4 3 5% 5% 20%	2315
	11th to 20th	Night	28% 24% 4 7% 4 3 3 2 3 4 17%	2545
	21st to end	Night	29% 24% 5% 7% 3 2 2 2 3 4 17%	2860
November	1st to 10th	Night	25% 33% 10% 10% 3 2 2 2 2 3 8%	2668
	11th to 20th	Night	23% 29% 10% 14% 3 3 2 2 3 3 9%	2985
	21st to end	Night	18% 30% 12% 18% 4 3 3 2 3 3 6%	3150
December	1st to 10th	Night	10% 19% 14% 31% 10% 3 2 1 1 2 5%	5050
	11th to 20th	Night	17% 22% 9% 26% 8% 4 2 2 2 3 5%	5731
	21st to end	Night	14% 19% 10% 24% 11% 7% 3 1 1 2 7%	7645

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	86% 4 3 6% 2	3535
	11th to 20th	Day	88% 3 5% 3 1	3700
	21st to end	Day	89% 2 1 3 2 2	4070
February	1st to 10th	Day	88% 3 3 4 2	1600
	11th to 20th	Day	86% 2 3 7% 2	1797
	21st to end	Day	79% 4 4 8% 5% 1	1650
March	1st to 10th	Day	77% 4 4 7% 7% 1	4478
	11th to 20th	Day	78% 4 4 9% 4 1	4646
	21st to end	Day	76% 3 4 11% 6%	5971
April	1st to 10th	Day	78% 5% 6% 8% 4	2400
	11th to 20th	Day	63% 6% 7% 16% 7% 1	2459
	21st to end	Day	64% 6% 7% 14% 8% 1	2654
May	1st to 10th	Day	66% 7% 5% 17% 4	6357
	11th to 20th	Day	54% 8% 12% 20% 7%	6322
	21st to end	Day	61% 4 11% 19% 4	7294
June	1st to 10th	Day	67% 7% 10% 13% 4	3000
	11th to 20th	Day	58% 7% 14% 17% 3	3000
	21st to end	Day	61% 5% 11% 16% 6% 1	3000
July	1st to 10th	Day	60% 4 10% 20% 6%	6725
	11th to 20th	Day	61% 3 14% 18% 4	6286
	21st to end	Day	60% 4 17% 17% 3	6730
August	1st to 10th	Day	58% 5% 16% 18% 3	4550
	11th to 20th	Day	52% 5% 14% 17% 9% 3	4425
	21st to end	Day	56% 4 15% 20% 5%	4454
September	1st to 10th	Day	56% 8% 12% 19% 6%	2400
	11th to 20th	Day	65% 4 13% 13% 4 1	2295
	21st to end	Day	64% 6% 12% 13% 5%	2200
October	1st to 10th	Day	61% 4 9% 18% 7% 1	3393
	11th to 20th	Day	77% 4 10% 7% 2	3001
	21st to end	Day	78% 4 7% 8% 3	3191
November	1st to 10th	Day	85% 3 6% 6% 1	1850
	11th to 20th	Day	80% 4 6% 8% 2	1632
	21st to end	Day	85% 4 5% 5% 1	1470
December	1st to 10th	Day	88% 2 4 5% 1	2360
	11th to 20th	Day	91% 3 4 2 1	2697
	21st to end	Day	85% 3 5% 6% 1	3575
January	1st to 10th	Night	88% 4 3 4 1	6646
	11th to 20th	Night	86% 3 5% 5% 1	6500
	21st to end	Night	89% 2 1 3 2 3	7150
February	1st to 10th	Night	90% 3 2 3 2 1	2801
	11th to 20th	Night	86% 5% 4 4 1	2498
	21st to end	Night	79% 4 4 7% 5%	1980
March	1st to 10th	Night	78% 4 4 7% 6% 1	5375
	11th to 20th	Night	81% 3 3 7% 5% 1	5312
	21st to end	Night	77% 4 6% 9% 4	4961
April	1st to 10th	Night	77% 5% 6% 9% 3	2000
	11th to 20th	Night	66% 6% 6% 14% 8%	1890
	21st to end	Night	64% 6% 10% 12% 8% 1	1744
May	1st to 10th	Night	69% 6% 7% 14% 4 1	3620
	11th to 20th	Night	54% 6% 9% 22% 9%	3597
	21st to end	Night	59% 5% 12% 20% 4	3599
June	1st to 10th	Night	65% 7% 9% 15% 4 1	1400
	11th to 20th	Night	56% 6% 13% 19% 5%	1400
	21st to end	Night	61% 6% 12% 16% 5%	1400
July	1st to 10th	Night	67% 3 9% 16% 4	3146
	11th to 20th	Night	60% 4 12% 18% 6%	3566
	21st to end	Night	61% 4 15% 18% 1	3831
August	1st to 10th	Night	64% 6% 13% 15% 2	2585
	11th to 20th	Night	61% 4 12% 13% 7% 4	2697
	21st to end	Night	56% 3 16% 20% 5%	3445
September	1st to 10th	Night	62% 6% 11% 18% 3	2000
	11th to 20th	Night	66% 5% 11% 13% 4 1	2105
	21st to end	Night	66% 6% 11% 14% 4	2200
October	1st to 10th	Night	60% 5% 10% 16% 9%	3783
	11th to 20th	Night	78% 3 7% 10% 2	4146
	21st to end	Night	75% 3 9% 9% 2 1	4610
November	1st to 10th	Night	85% 5% 4 5% 1	2668
	11th to 20th	Night	83% 3 6% 6% 2	2985
	21st to end	Night	86% 4 4 5% 1	3150
December	1st to 10th	Night	90% 2 4 4	5050
	11th to 20th	Night	88% 3 5% 2 1	5733
	21st to end	Night	86% 3 4 5% 1	7645

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	26% 31% 26% 10% 6% 1	430
	11th to 20th	Day	29% 26% 26% 13% 5% 2	430
	21st to end	Day	27% 33% 26% 11% 3	473
February	1st to 10th	Day	28% 32% 23% 11% 6%	400
	11th to 20th	Day	29% 35% 25% 8% 3 1	396
	21st to end	Day	24% 30% 28% 12% 4 1	331
March	1st to 10th	Day	24% 32% 29% 10% 4 2	400
	11th to 20th	Day	30% 26% 21% 14% 7% 1	408
	21st to end	Day	32% 24% 27% 12% 4 1	550
April	1st to 10th	Day	33% 28% 28% 9% 2	500
	11th to 20th	Day	26% 22% 30% 15% 6% 1	577
	21st to end	Day	31% 20% 24% 19% 4 1	700
May	1st to 10th	Day	33% 17% 23% 19% 6% 1	703
	11th to 20th	Day	25% 17% 26% 21% 9% 2	724
	21st to end	Day	33% 15% 28% 16% 7% 1	790
June	1st to 10th	Day	35% 16% 24% 17% 7% 1	730
	11th to 20th	Day	33% 13% 27% 18% 7% 2	730
	21st to end	Day	36% 14% 23% 17% 8% 2	730
July	1st to 10th	Day	34% 13% 27% 16% 8% 2	720
	11th to 20th	Day	30% 14% 28% 19% 8% 1	718
	21st to end	Day	34% 13% 25% 20% 7% 1	795
August	1st to 10th	Day	29% 12% 27% 20% 9% 2	725
	11th to 20th	Day	29% 13% 29% 19% 9% 2	717
	21st to end	Day	33% 14% 29% 16% 7% 2	673
September	1st to 10th	Day	34% 20% 26% 16% 4 1	530
	11th to 20th	Day	42% 18% 25% 13% 3	472
	21st to end	Day	40% 19% 26% 10% 2 1	420
October	1st to 10th	Day	36% 24% 25% 9% 4 1	420
	11th to 20th	Day	44% 15% 20% 14% 6% 1	420
	21st to end	Day	43% 18% 21% 11% 6% 1	462
November	1st to 10th	Day	46% 26% 19% 6% 2	425
	11th to 20th	Day	40% 22% 22% 11% 4 1	430
	21st to end	Day	40% 27% 24% 8% 1	430
December	1st to 10th	Day	33% 26% 25% 11% 4	430
	11th to 20th	Day	34% 33% 20% 8% 3	430
	21st to end	Day	28% 29% 24% 13% 4 1	473
January	1st to 10th	Night	26% 33% 23% 13% 5% 1	950
	11th to 20th	Night	29% 28% 25% 14% 4 1	950
	21st to end	Night	24% 29% 30% 12% 4 1	1045
February	1st to 10th	Night	24% 33% 24% 14% 4	901
	11th to 20th	Night	25% 29% 29% 13% 3 1	793
	21st to end	Night	21% 23% 31% 16% 7% 2	660
March	1st to 10th	Night	24% 28% 29% 16% 3 1	800
	11th to 20th	Night	26% 21% 26% 21% 7%	765
	21st to end	Night	27% 22% 29% 16% 6% 1	660
April	1st to 10th	Night	35% 19% 23% 19% 4 1	600
	11th to 20th	Night	26% 17% 27% 21% 7% 1	594
	21st to end	Night	30% 13% 28% 22% 6% 2	600
May	1st to 10th	Night	33% 11% 20% 24% 9% 2	600
	11th to 20th	Night	30% 14% 21% 24% 11% 1	592
	21st to end	Night	34% 10% 23% 26% 7% 1	649
June	1st to 10th	Night	32% 13% 20% 27% 9% 1	600
	11th to 20th	Night	26% 13% 24% 26% 10% 1	600
	21st to end	Night	32% 9% 25% 24% 9% 1	600
July	1st to 10th	Night	36% 7% 23% 22% 12% 1	586
	11th to 20th	Night	36% 8% 19% 26% 11% 1	582
	21st to end	Night	32% 8% 22% 28% 10%	656
August	1st to 10th	Night	29% 8% 19% 30% 13% 1	598
	11th to 20th	Night	32% 9% 22% 24% 12% 1	592
	21st to end	Night	34% 8% 20% 23% 14% 1	660
September	1st to 10th	Night	37% 13% 22% 22% 7%	600
	11th to 20th	Night	43% 10% 23% 21% 4	600
	21st to end	Night	44% 15% 22% 14% 5% 1	600
October	1st to 10th	Night	38% 16% 26% 15% 4 1	715
	11th to 20th	Night	44% 14% 17% 16% 8% 1	880
	21st to end	Night	44% 16% 17% 15% 6% 1	1001
November	1st to 10th	Night	45% 24% 17% 11% 2	930
	11th to 20th	Night	41% 25% 18% 11% 5% 1	950
	21st to end	Night	39% 27% 21% 10% 2	950
December	1st to 10th	Night	33% 25% 24% 14% 4	950
	11th to 20th	Night	36% 28% 22% 11% 2	950
	21st to end	Night	27% 27% 25% 14% 6% 1	1045

Page generated at 2026-01-29 02:21:42. Version ac07

Copyright © 2026 Attilla Danko.