Beaverlodge
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Beaverlodge clear sky chart from 2005-11-06 to 2024-02-05.

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	11% 10% 4 8% 7% 4 6% 6% 6% 8% 32%	77239
	Night	9% 11% 5% 8% 7% 4 6% 6% 6% 8% 30%	81548
Transparency	Day	49% 8% 15% 20% 8% 1	76920
	Night	50% 8% 13% 19% 8% 1	81447
Seeing	Day	16% 9% 25% 27% 18% 6%	15408
	Night	15% 8% 27% 32% 15% 2	23656

By Month

Percentage Cloud Cover NW (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	5% 13% 7% 14% 11% 5% 5% 6% 5% 7% 20%	1899
	11th to 20th	Day	8% 13% 4 8% 6% 6% 9% 7% 9% 6% 22%	1960
	21st to end	Day	8% 12% 4 6% 7% 4 6% 6% 7% 9% 31%	2537
February	1st to 10th	Day	8% 12% 7% 10% 8% 5% 6% 6% 6% 8% 24%	1472
	11th to 20th	Day	6% 14% 8% 11% 8% 4 7% 5% 6% 7% 24%	1474
	21st to end	Day	6% 12% 7% 10% 10% 6% 7% 6% 6% 6% 25%	1386
March	1st to 10th	Day	6% 11% 5% 11% 10% 6% 6% 6% 6% 7% 27%	1800
	11th to 20th	Day	9% 13% 6% 9% 7% 3 5% 6% 6% 8% 29%	1858
	21st to end	Day	8% 16% 6% 11% 6% 4 5% 6% 7% 6% 24%	2361
April	1st to 10th	Day	5% 9% 5% 10% 9% 5% 6% 7% 6% 9% 28%	2160
	11th to 20th	Day	8% 13% 6% 9% 7% 3 6% 5% 6% 7% 30%	2309
	21st to end	Day	11% 12% 4 9% 6% 3 6% 5% 6% 8% 29%	2520
May	1st to 10th	Day	12% 10% 4 9% 7% 4 5% 6% 6% 7% 31%	2520
	11th to 20th	Day	11% 8% 3 6% 6% 4 7% 6% 5% 8% 36%	2671
	21st to end	Day	16% 8% 3 6% 6% 4 6% 5% 6% 7% 33%	3111
June	1st to 10th	Day	14% 7% 4 6% 6% 4 6% 5% 6% 7% 33%	2880
	11th to 20th	Day	18% 9% 3 8% 6% 4 6% 5% 6% 7% 28%	2880
	21st to end	Day	11% 6% 3 6% 7% 4 6% 5% 7% 9% 36%	2880
July	1st to 10th	Day	14% 6% 3 5% 5% 3 5% 6% 7% 8% 37%	2880
	11th to 20th	Day	13% 6% 3 5% 7% 3 7% 6% 6% 9% 35%	2880
	21st to end	Day	11% 5% 3 5% 6% 3 5% 5% 7% 8% 41%	3020
August	1st to 10th	Day	11% 6% 2 6% 7% 4 5% 6% 6% 9% 39%	2507
	11th to 20th	Day	9% 4 3 5% 6% 4 5% 5% 6% 8% 44%	2475
	21st to end	Day	12% 8% 3 5% 6% 4 5% 6% 6% 8% 36%	2626
September	1st to 10th	Day	14% 7% 2 6% 6% 3 4 5% 5% 8% 41%	2160
	11th to 20th	Day	14% 7% 2 5% 5% 3 5% 4 5% 8% 40%	2148
	21st to end	Day	12% 6% 2 6% 5% 4 5% 5% 6% 9% 39%	1944
October	1st to 10th	Day	13% 10% 4 8% 7% 4 4 5% 5% 7% 34%	1800
	11th to 20th	Day	12% 9% 3 8% 7% 4 6% 6% 7% 7% 30%	1671
	21st to end	Day	12% 13% 5% 8% 6% 3 5% 4 6% 7% 32%	1728
November	1st to 10th	Day	13% 16% 5% 8% 6% 3 3 6% 6% 7% 26%	1446
	11th to 20th	Day	12% 14% 5% 9% 8% 4 4 5% 5% 6% 29%	1330
	21st to end	Day	10% 12% 4 11% 10% 4 5% 5% 5% 8% 27%	1274
December	1st to 10th	Day	10% 13% 5% 8% 8% 4 5% 6% 6% 6% 30%	1140
	11th to 20th	Day	13% 14% 4 8% 8% 4 6% 6% 5% 7% 25%	1442
	21st to end	Day	6% 9% 3 8% 6% 3 6% 6% 8% 10% 35%	2090
January	1st to 10th	Night	5% 14% 7% 15% 10% 3 4 5% 6% 7% 23%	5046
	11th to 20th	Night	6% 12% 5% 8% 9% 5% 7% 9% 10% 9% 22%	4952
	21st to end	Night	10% 16% 5% 7% 6% 4 6% 6% 6% 9% 25%	5118
February	1st to 10th	Night	9% 14% 6% 9% 8% 4 5% 5% 6% 7% 25%	2582
	11th to 20th	Night	7% 13% 6% 11% 7% 4 7% 6% 6% 8% 24%	2371
	21st to end	Night	5% 12% 7% 11% 8% 4 7% 6% 5% 8% 27%	1870
March	1st to 10th	Night	5% 12% 6% 11% 9% 4 6% 5% 6% 7% 30%	2160
	11th to 20th	Night	9% 13% 5% 8% 7% 4 5% 5% 5% 8% 30%	2097
	21st to end	Night	8% 13% 6% 9% 7% 4 5% 5% 6% 9% 28%	1995
April	1st to 10th	Night	5% 11% 5% 10% 8% 4 8% 7% 7% 8% 28%	1800
	11th to 20th	Night	10% 10% 5% 9% 6% 4 6% 5% 6% 7% 32%	1597
	21st to end	Night	11% 10% 4 7% 6% 4 7% 6% 7% 5% 33%	1440
May	1st to 10th	Night	14% 9% 4 7% 6% 3 5% 6% 5% 6% 34%	1440
	11th to 20th	Night	11% 9% 3 6% 5% 5% 5% 6% 7% 7% 36%	1220
	21st to end	Night	14% 9% 3 6% 7% 3 5% 4 5% 8% 35%	1164
June	1st to 10th	Night	13% 7% 5% 8% 7% 4 5% 4 6% 7% 35%	1080
	11th to 20th	Night	20% 6% 3 6% 7% 3 7% 5% 7% 10% 27%	1080
	21st to end	Night	12% 5% 3 5% 7% 4 5% 6% 7% 10% 36%	1080
July	1st to 10th	Night	12% 5% 3 6% 5% 3 6% 4 8% 8% 39%	1080
	11th to 20th	Night	12% 6% 3 6% 6% 4 6% 6% 8% 10% 34%	1080
	21st to end	Night	9% 4 2 6% 6% 3 6% 7% 7% 9% 41%	1294
August	1st to 10th	Night	9% 4 3 5% 6% 3 5% 6% 6% 10% 43%	1432
	11th to 20th	Night	6% 3 3 4 6% 4 6% 7% 8% 9% 46%	1424
	21st to end	Night	13% 6% 3 6% 5% 4 6% 6% 7% 8% 36%	1727
September	1st to 10th	Night	13% 6% 3 7% 6% 4 5% 4 6% 6% 39%	1800
	11th to 20th	Night	12% 9% 2 5% 5% 3 4 4 6% 8% 42%	1812
	21st to end	Night	13% 7% 3 6% 5% 4 5% 5% 6% 7% 38%	2014
October	1st to 10th	Night	13% 12% 3 7% 6% 4 5% 5% 6% 8% 33%	2160
	11th to 20th	Night	11% 9% 4 8% 7% 4 6% 5% 5% 8% 33%	2288
	21st to end	Night	13% 12% 5% 8% 6% 3 5% 5% 6% 6% 30%	2624
November	1st to 10th	Night	14% 14% 5% 8% 7% 4 5% 5% 6% 7% 26%	2613
	11th to 20th	Night	10% 14% 6% 10% 7% 4 5% 4 5% 7% 28%	2850
	21st to end	Night	10% 14% 6% 9% 8% 4 5% 4 6% 6% 28%	2902
December	1st to 10th	Night	8% 10% 6% 9% 9% 5% 5% 6% 5% 7% 31%	3040
	11th to 20th	Night	10% 16% 5% 10% 7% 4 7% 5% 5% 7% 24%	3750
	21st to end	Night	5% 11% 4 9% 8% 5% 7% 6% 5% 8% 33%	5566

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	61% 7% 13% 17% 2 1	1899
	11th to 20th	Day	56% 7% 12% 10% 14% 2	1978
	21st to end	Day	46% 12% 21% 15% 7%	2537
February	1st to 10th	Day	55% 8% 13% 12% 11% 1	1472
	11th to 20th	Day	58% 8% 13% 15% 6%	1482
	21st to end	Day	58% 6% 12% 16% 6% 1	1386
March	1st to 10th	Day	54% 8% 11% 19% 8% 1	1800
	11th to 20th	Day	52% 7% 12% 20% 9% 1	1858
	21st to end	Day	57% 9% 14% 14% 5%	2361
April	1st to 10th	Day	50% 8% 15% 18% 8% 1	2160
	11th to 20th	Day	53% 6% 13% 18% 9% 1	2309
	21st to end	Day	51% 8% 11% 21% 7% 1	2520
May	1st to 10th	Day	51% 8% 13% 18% 9% 1	2520
	11th to 20th	Day	44% 8% 13% 22% 12% 2	2675
	21st to end	Day	49% 7% 13% 20% 9% 2	3112
June	1st to 10th	Day	48% 7% 13% 21% 10%	2880
	11th to 20th	Day	55% 8% 10% 18% 9%	2880
	21st to end	Day	43% 9% 14% 23% 10% 1	2880
July	1st to 10th	Day	42% 9% 16% 23% 10% 1	2801
	11th to 20th	Day	44% 10% 19% 22% 5%	2793
	21st to end	Day	37% 11% 20% 25% 6%	2851
August	1st to 10th	Day	41% 10% 21% 24% 5%	2490
	11th to 20th	Day	36% 8% 20% 28% 7%	2475
	21st to end	Day	44% 9% 17% 24% 6%	2626
September	1st to 10th	Day	43% 8% 19% 23% 6% 1	2160
	11th to 20th	Day	42% 8% 17% 25% 7%	2148
	21st to end	Day	41% 9% 15% 24% 10% 1	1944
October	1st to 10th	Day	51% 6% 15% 22% 6%	1800
	11th to 20th	Day	49% 9% 15% 22% 6%	1671
	21st to end	Day	52% 6% 16% 20% 7%	1728
November	1st to 10th	Day	56% 8% 11% 18% 6% 1	1446
	11th to 20th	Day	56% 6% 15% 15% 8%	1330
	21st to end	Day	56% 7% 13% 16% 7% 2	1274
December	1st to 10th	Day	54% 6% 12% 16% 10% 1	1140
	11th to 20th	Day	58% 8% 11% 16% 7%	1444
	21st to end	Day	40% 8% 14% 24% 11% 2	2090
January	1st to 10th	Night	59% 7% 10% 16% 7% 1	5046
	11th to 20th	Night	54% 6% 12% 11% 16% 1	4996
	21st to end	Night	53% 10% 18% 14% 6%	5118
February	1st to 10th	Night	57% 6% 13% 14% 9%	2582
	11th to 20th	Night	56% 9% 11% 19% 6%	2373
	21st to end	Night	54% 7% 12% 19% 7% 1	1870
March	1st to 10th	Night	52% 6% 13% 20% 8% 1	2160
	11th to 20th	Night	51% 6% 12% 22% 9% 1	2098
	21st to end	Night	52% 8% 12% 19% 8%	1995
April	1st to 10th	Night	50% 7% 14% 19% 10% 1	1800
	11th to 20th	Night	49% 8% 12% 20% 10% 2	1597
	21st to end	Night	49% 8% 10% 22% 10% 1	1440
May	1st to 10th	Night	49% 7% 12% 21% 11% 1	1440
	11th to 20th	Night	43% 9% 9% 22% 15% 1	1220
	21st to end	Night	47% 7% 12% 22% 11% 1	1164
June	1st to 10th	Night	48% 7% 11% 24% 10%	1080
	11th to 20th	Night	50% 8% 14% 21% 6% 1	1080
	21st to end	Night	42% 8% 18% 21% 11%	1080
July	1st to 10th	Night	38% 9% 16% 27% 9% 1	1050
	11th to 20th	Night	44% 10% 17% 24% 5%	1044
	21st to end	Night	33% 12% 23% 27% 4	1223
August	1st to 10th	Night	35% 10% 22% 25% 7%	1424
	11th to 20th	Night	31% 12% 20% 29% 7% 1	1424
	21st to end	Night	43% 9% 17% 23% 6% 1	1727
September	1st to 10th	Night	44% 9% 17% 23% 6% 1	1800
	11th to 20th	Night	39% 7% 17% 28% 8%	1812
	21st to end	Night	44% 9% 13% 22% 12% 1	2014
October	1st to 10th	Night	50% 7% 15% 21% 7% 1	2160
	11th to 20th	Night	48% 9% 14% 24% 5%	2288
	21st to end	Night	53% 8% 13% 17% 9%	2624
November	1st to 10th	Night	57% 7% 11% 18% 5% 1	2613
	11th to 20th	Night	55% 8% 12% 16% 9%	2850
	21st to end	Night	55% 7% 12% 17% 7% 2	2902
December	1st to 10th	Night	52% 7% 12% 17% 11% 1	3040
	11th to 20th	Night	60% 7% 11% 14% 7%	3747
	21st to end	Night	47% 8% 12% 23% 8% 2	5566

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	12% 7% 18% 41% 16% 6%	180
	11th to 20th	Day	17% 9% 23% 31% 17% 4	180
	21st to end	Day	11% 11% 28% 32% 16% 3	198
February	1st to 10th	Day	10% 16% 22% 32% 17% 3	168
	11th to 20th	Day	12% 16% 23% 29% 17% 3	234
	21st to end	Day	10% 11% 24% 32% 20% 3	304
March	1st to 10th	Day	9% 11% 27% 28% 20% 5%	420
	11th to 20th	Day	11% 7% 26% 33% 15% 7%	420
	21st to end	Day	17% 9% 24% 24% 21% 4	462
April	1st to 10th	Day	8% 13% 31% 30% 13% 6%	420
	11th to 20th	Day	15% 11% 24% 31% 12% 7%	412
	21st to end	Day	20% 13% 26% 20% 17% 4	420
May	1st to 10th	Day	17% 12% 28% 27% 13% 4	423
	11th to 20th	Day	15% 6% 21% 31% 22% 5%	641
	21st to end	Day	16% 7% 23% 26% 22% 6%	874
June	1st to 10th	Day	16% 11% 26% 28% 15% 3	810
	11th to 20th	Day	23% 7% 22% 23% 19% 5%	810
	21st to end	Day	15% 8% 23% 25% 20% 10%	810
July	1st to 10th	Day	16% 6% 22% 28% 22% 6%	796
	11th to 20th	Day	15% 5% 25% 28% 20% 7%	792
	21st to end	Day	12% 9% 22% 32% 18% 8%	766
August	1st to 10th	Day	15% 7% 18% 28% 20% 12%	447
	11th to 20th	Day	11% 12% 30% 23% 17% 7%	437
	21st to end	Day	17% 9% 29% 22% 15% 8%	495
September	1st to 10th	Day	19% 10% 24% 25% 16% 6%	450
	11th to 20th	Day	17% 9% 26% 23% 18% 6%	450
	21st to end	Day	15% 14% 31% 22% 13% 4	450
October	1st to 10th	Day	18% 13% 23% 24% 16% 6%	450
	11th to 20th	Day	21% 9% 26% 24% 15% 5%	321
	21st to end	Day	19% 11% 24% 25% 14% 6%	270
November	1st to 10th	Day	19% 12% 23% 26% 18% 2	180
	11th to 20th	Day	23% 6% 27% 29% 14% 1	180
	21st to end	Day	16% 10% 28% 33% 9% 3	180
December	1st to 10th	Day	10% 7% 31% 34% 12% 5%	180
	11th to 20th	Day	17% 13% 23% 28% 18% 2	180
	21st to end	Day	15% 6% 25% 30% 21% 3	198
January	1st to 10th	Night	14% 9% 27% 31% 15% 3	1040
	11th to 20th	Night	14% 12% 27% 31% 14% 2	1002
	21st to end	Night	19% 12% 29% 29% 10% 1	908
February	1st to 10th	Night	18% 12% 23% 27% 15% 4	738
	11th to 20th	Night	14% 9% 28% 32% 15% 2	704
	21st to end	Night	10% 9% 23% 35% 18% 5%	592
March	1st to 10th	Night	9% 10% 28% 31% 19% 3	720
	11th to 20th	Night	14% 6% 27% 36% 14% 2	720
	21st to end	Night	14% 6% 23% 33% 21% 3	792
April	1st to 10th	Night	11% 8% 29% 34% 15% 3	720
	11th to 20th	Night	13% 8% 26% 34% 17% 2	529
	21st to end	Night	15% 10% 30% 28% 16% 1	360
May	1st to 10th	Night	16% 8% 26% 36% 13% 2	360
	11th to 20th	Night	15% 6% 27% 34% 16% 2	354
	21st to end	Night	15% 6% 25% 31% 21% 2	389
June	1st to 10th	Night	13% 9% 28% 30% 20%	360
	11th to 20th	Night	22% 5% 19% 33% 18% 3	360
	21st to end	Night	14% 3 27% 33% 21% 3	360
July	1st to 10th	Night	14% 3 21% 40% 21% 2	350
	11th to 20th	Night	16% 5% 24% 30% 23% 3	348
	21st to end	Night	11% 2 21% 38% 24% 4	394
August	1st to 10th	Night	11% 4 20% 31% 30% 4	358
	11th to 20th	Night	6% 4 30% 35% 22% 3	356
	21st to end	Night	16% 6% 27% 29% 20% 2	539
September	1st to 10th	Night	17% 5% 25% 34% 18% 2	720
	11th to 20th	Night	17% 6% 23% 32% 20% 3	720
	21st to end	Night	17% 9% 29% 29% 14% 2	720
October	1st to 10th	Night	19% 7% 29% 30% 13% 1	720
	11th to 20th	Night	16% 8% 29% 35% 11% 2	720
	21st to end	Night	20% 12% 29% 29% 9% 1	792
November	1st to 10th	Night	19% 8% 29% 30% 13% 2	763
	11th to 20th	Night	15% 13% 35% 27% 8% 1	950
	21st to end	Night	16% 11% 31% 30% 10% 2	974
December	1st to 10th	Night	12% 10% 32% 33% 11% 3	1040
	11th to 20th	Night	14% 10% 28% 30% 14% 4	1040
	21st to end	Night	14% 9% 25% 36% 15% 2	1144

Page generated at 2024-02-02 03:20:31. Version ac07

Copyright 2024 Attilla Danko