Caribou
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Caribou clear sky chart from 2005-11-06 to 2024-01-31.

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	18% 8% 3 7% 6% 4 5% 5% 6% 7% 31%	74749
	Night	18% 10% 4 7% 6% 3 5% 5% 5% 6% 32%	75382
Transparency	Day	52% 4 13% 21% 9% 1	74443
	Night	54% 4 12% 20% 9% 1	75223
Seeing	Day	23% 13% 29% 23% 10% 2	14877
	Night	22% 10% 31% 28% 8% 1	23076

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% 13% 5% 10% 8% 5% 5% 5% 5% 6% 21%	1331
	11th to 20th	Day	17% 14% 5% 10% 7% 3 4 5% 5% 6% 24%	1520
	21st to end	Day	10% 10% 5% 7% 6% 4 6% 7% 7% 8% 31%	1664
February	1st to 10th	Day	12% 13% 5% 6% 7% 4 7% 6% 7% 7% 25%	1603
	11th to 20th	Day	16% 11% 5% 8% 6% 4 7% 6% 6% 7% 24%	1587
	21st to end	Day	12% 8% 4 7% 8% 5% 6% 7% 6% 8% 30%	1480
March	1st to 10th	Day	16% 9% 4 8% 7% 4 5% 5% 6% 7% 29%	1822
	11th to 20th	Day	17% 10% 3 7% 7% 4 6% 7% 5% 6% 28%	1980
	21st to end	Day	15% 12% 5% 8% 7% 2 5% 4 5% 6% 32%	2178
April	1st to 10th	Day	20% 10% 3 7% 7% 4 6% 5% 5% 6% 25%	2156
	11th to 20th	Day	19% 8% 3 6% 5% 3 4 4 6% 6% 35%	2312
	21st to end	Day	25% 10% 3 5% 5% 3 4 4 5% 6% 31%	2340
May	1st to 10th	Day	24% 7% 3 7% 5% 4 5% 4 5% 6% 30%	2340
	11th to 20th	Day	24% 7% 2 5% 5% 3 5% 5% 5% 6% 34%	2426
	21st to end	Day	19% 6% 3 6% 5% 4 5% 5% 7% 7% 32%	2919
June	1st to 10th	Day	21% 8% 3 6% 6% 4 6% 5% 7% 8% 26%	2700
	11th to 20th	Day	19% 6% 3 7% 5% 3 5% 5% 5% 7% 34%	2700
	21st to end	Day	23% 9% 4 7% 6% 4 6% 5% 5% 7% 25%	2700
July	1st to 10th	Day	16% 6% 2 6% 7% 4 6% 6% 7% 10% 29%	2700
	11th to 20th	Day	15% 5% 3 6% 6% 3 6% 6% 7% 8% 32%	2658
	21st to end	Day	15% 6% 3 5% 7% 4 6% 6% 7% 9% 31%	2744
August	1st to 10th	Day	18% 6% 2 5% 5% 3 6% 6% 7% 10% 32%	2338
	11th to 20th	Day	14% 7% 3 7% 6% 4 5% 6% 7% 7% 34%	2304
	21st to end	Day	15% 6% 3 5% 6% 4 5% 5% 6% 8% 37%	2574
September	1st to 10th	Day	16% 6% 3 5% 6% 2 5% 3 6% 7% 41%	2139
	11th to 20th	Day	18% 5% 2 4 4 3 4 4 4 6% 47%	1980
	21st to end	Day	17% 5% 2 5% 5% 2 4 5% 5% 8% 41%	1980
October	1st to 10th	Day	17% 8% 3 6% 5% 4 4 4 4 8% 38%	1885
	11th to 20th	Day	22% 8% 4 6% 5% 3 4 4 5% 6% 32%	1782
	21st to end	Day	25% 9% 4 7% 7% 3 5% 4 5% 7% 25%	1782
November	1st to 10th	Day	20% 10% 4 6% 6% 4 5% 4 4 6% 31%	1657
	11th to 20th	Day	20% 9% 3 8% 6% 4 6% 5% 5% 7% 27%	1520
	21st to end	Day	21% 11% 3 8% 5% 4 5% 4 6% 7% 26%	1519
December	1st to 10th	Day	22% 11% 5% 7% 7% 4 6% 4 5% 6% 24%	1330
	11th to 20th	Day	20% 11% 4 8% 7% 4 5% 5% 5% 6% 25%	1668
	21st to end	Day	20% 13% 4 9% 6% 3 4 4 4 5% 28%	2431
January	1st to 10th	Night	15% 13% 5% 11% 8% 4 6% 6% 5% 6% 20%	2831
	11th to 20th	Night	16% 15% 6% 8% 7% 4 5% 5% 6% 5% 23%	2660
	21st to end	Night	10% 12% 3 7% 7% 5% 7% 6% 6% 8% 30%	2919
February	1st to 10th	Night	13% 13% 5% 7% 7% 5% 6% 5% 5% 7% 27%	2355
	11th to 20th	Night	14% 13% 6% 9% 8% 4 6% 5% 5% 6% 25%	2257
	21st to end	Night	13% 13% 4 8% 7% 4 5% 4 4 5% 34%	1776
March	1st to 10th	Night	14% 10% 4 8% 7% 3 5% 5% 5% 7% 31%	2124
	11th to 20th	Night	16% 11% 5% 7% 7% 4 5% 5% 4 6% 31%	1979
	21st to end	Night	16% 10% 4 8% 6% 3 4 5% 5% 6% 31%	2178
April	1st to 10th	Night	23% 11% 4 6% 6% 4 4 3 4 5% 31%	1800
	11th to 20th	Night	20% 8% 2 5% 6% 3 4 5% 5% 7% 35%	1598
	21st to end	Night	26% 10% 3 4 5% 3 4 4 4 5% 31%	1620
May	1st to 10th	Night	22% 10% 2 5% 5% 3 5% 5% 5% 7% 30%	1620
	11th to 20th	Night	24% 6% 3 6% 5% 4 5% 4 4 5% 34%	1481
	21st to end	Night	19% 7% 2 6% 5% 3 4 4 5% 6% 36%	1356
June	1st to 10th	Night	25% 7% 3 6% 5% 2 5% 5% 4 7% 32%	1260
	11th to 20th	Night	18% 6% 1 5% 5% 3 5% 4 8% 8% 38%	1260
	21st to end	Night	22% 7% 4 6% 6% 3 3 5% 5% 5% 33%	1260
July	1st to 10th	Night	15% 8% 3 5% 6% 3 4 4 5% 8% 37%	1260
	11th to 20th	Night	16% 5% 3 6% 4 3 5% 6% 7% 8% 37%	1300
	21st to end	Night	17% 7% 3 6% 5% 3 5% 5% 6% 7% 36%	1574
August	1st to 10th	Night	14% 8% 3 4 5% 3 6% 5% 7% 7% 39%	1581
	11th to 20th	Night	12% 5% 3 7% 7% 4 5% 6% 6% 9% 35%	1596
	21st to end	Night	11% 4 3 6% 4 4 4 5% 6% 7% 46%	1782
September	1st to 10th	Night	15% 4 2 5% 5% 3 4 4 5% 8% 44%	1818
	11th to 20th	Night	16% 6% 2 4 5% 3 4 5% 6% 6% 45%	1980
	21st to end	Night	18% 5% 2 4 4 2 4 4 4 6% 46%	1980
October	1st to 10th	Night	20% 6% 2 4 5% 3 3 4 4 6% 43%	2074
	11th to 20th	Night	21% 8% 3 5% 5% 3 4 4 5% 7% 35%	2173
	21st to end	Night	24% 9% 3 6% 6% 3 4 5% 5% 6% 31%	2574
November	1st to 10th	Night	20% 9% 4 5% 6% 3 5% 5% 5% 6% 33%	2419
	11th to 20th	Night	20% 9% 4 6% 5% 3 4 5% 5% 7% 31%	2660
	21st to end	Night	20% 9% 4 8% 7% 4 6% 5% 5% 6% 26%	2660
December	1st to 10th	Night	23% 12% 4 8% 7% 3 4 4 4 5% 25%	2850
	11th to 20th	Night	24% 10% 3 7% 6% 4 5% 5% 4 6% 25%	3531
	21st to end	Night	21% 14% 4 7% 6% 3 5% 5% 5% 6% 26%	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	64% 4 10% 16% 6%	1332
	11th to 20th	Day	62% 3 11% 17% 7%	1520
	21st to end	Day	49% 4 13% 21% 12% 1	1664
February	1st to 10th	Day	56% 5% 12% 17% 9% 1	1603
	11th to 20th	Day	59% 4 12% 18% 7% 1	1595
	21st to end	Day	51% 5% 10% 23% 9% 2	1480
March	1st to 10th	Day	54% 4 12% 19% 11% 1	1826
	11th to 20th	Day	54% 3 13% 18% 10% 2	1980
	21st to end	Day	54% 3 9% 22% 10% 2	2178
April	1st to 10th	Day	57% 4 10% 18% 9% 2	2156
	11th to 20th	Day	48% 3 11% 24% 12% 2	2312
	21st to end	Day	55% 3 9% 19% 11% 3	2340
May	1st to 10th	Day	55% 3 9% 20% 13% 1	2340
	11th to 20th	Day	52% 3 11% 21% 12% 1	2430
	21st to end	Day	49% 6% 12% 22% 10% 1	2919
June	1st to 10th	Day	53% 5% 15% 16% 10% 1	2700
	11th to 20th	Day	49% 4 14% 20% 12% 2	2700
	21st to end	Day	58% 5% 12% 16% 8%	2700
July	1st to 10th	Day	48% 5% 18% 21% 7% 1	2625
	11th to 20th	Day	46% 6% 15% 25% 8%	2577
	21st to end	Day	48% 5% 16% 23% 8%	2591
August	1st to 10th	Day	46% 7% 19% 22% 6%	2324
	11th to 20th	Day	47% 6% 16% 25% 6%	2304
	21st to end	Day	44% 4 15% 27% 9%	2574
September	1st to 10th	Day	43% 4 15% 26% 12%	2139
	11th to 20th	Day	41% 3 13% 27% 15%	1980
	21st to end	Day	42% 5% 12% 28% 12%	1980
October	1st to 10th	Day	48% 3 11% 28% 9%	1885
	11th to 20th	Day	53% 4 16% 21% 6%	1782
	21st to end	Day	59% 4 13% 16% 8%	1782
November	1st to 10th	Day	55% 3 12% 22% 8%	1657
	11th to 20th	Day	56% 5% 11% 19% 8%	1520
	21st to end	Day	60% 3 17% 18% 3	1519
December	1st to 10th	Day	61% 3 15% 15% 6%	1330
	11th to 20th	Day	62% 3 9% 18% 9%	1668
	21st to end	Day	62% 3 11% 16% 6% 2	2431
January	1st to 10th	Night	66% 4 10% 14% 5%	2831
	11th to 20th	Night	63% 5% 10% 14% 7% 1	2660
	21st to end	Night	53% 4 10% 22% 10% 1	2919
February	1st to 10th	Night	57% 5% 11% 16% 10% 1	2355
	11th to 20th	Night	61% 4 9% 16% 8% 1	2260
	21st to end	Night	55% 3 8% 20% 13% 1	1776
March	1st to 10th	Night	54% 4 9% 23% 9% 1	2133
	11th to 20th	Night	56% 3 9% 18% 13% 1	1980
	21st to end	Night	54% 3 8% 21% 11% 3	2178
April	1st to 10th	Night	57% 4 8% 17% 12% 3	1800
	11th to 20th	Night	49% 3 10% 21% 16% 2	1598
	21st to end	Night	56% 3 7% 17% 15% 2	1620
May	1st to 10th	Night	53% 4 9% 18% 15% 2	1620
	11th to 20th	Night	53% 3 10% 22% 11% 1	1482
	21st to end	Night	49% 5% 11% 20% 15%	1357
June	1st to 10th	Night	52% 4 11% 23% 8% 1	1260
	11th to 20th	Night	44% 5% 15% 22% 13% 2	1260
	21st to end	Night	54% 5% 13% 17% 10% 1	1260
July	1st to 10th	Night	46% 4 18% 24% 8%	1225
	11th to 20th	Night	42% 6% 16% 26% 9% 1	1258
	21st to end	Night	47% 5% 16% 22% 9% 1	1486
August	1st to 10th	Night	44% 5% 20% 26% 5%	1571
	11th to 20th	Night	46% 6% 20% 22% 6%	1596
	21st to end	Night	36% 5% 17% 32% 10%	1782
September	1st to 10th	Night	40% 4 14% 29% 12% 1	1818
	11th to 20th	Night	41% 4 14% 27% 14%	1980
	21st to end	Night	40% 5% 13% 27% 15% 1	1980
October	1st to 10th	Night	44% 3 11% 29% 11% 1	2074
	11th to 20th	Night	51% 3 14% 24% 8%	2173
	21st to end	Night	55% 4 13% 20% 8%	2574
November	1st to 10th	Night	53% 4 14% 22% 8%	2419
	11th to 20th	Night	55% 4 13% 18% 10% 1	2660
	21st to end	Night	60% 5% 15% 14% 5% 1	2660
December	1st to 10th	Night	64% 3 11% 18% 4	2850
	11th to 20th	Night	63% 3 10% 18% 7%	3532
	21st to end	Night	61% 3 10% 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	21% 18% 29% 25% 7%	180
	11th to 20th	Day	28% 16% 30% 17% 8%	180
	21st to end	Day	19% 15% 33% 18% 11% 5%	196
February	1st to 10th	Day	25% 13% 31% 25% 7%	323
	11th to 20th	Day	18% 16% 39% 23% 5%	342
	21st to end	Day	16% 18% 34% 25% 8%	346
March	1st to 10th	Day	25% 13% 33% 24% 6%	420
	11th to 20th	Day	21% 15% 29% 23% 10% 1	420
	21st to end	Day	23% 15% 28% 22% 10% 2	462
April	1st to 10th	Day	28% 17% 27% 18% 8% 1	420
	11th to 20th	Day	22% 11% 30% 24% 9% 2	412
	21st to end	Day	31% 12% 23% 23% 9% 2	420
May	1st to 10th	Day	28% 16% 27% 22% 7% 1	423
	11th to 20th	Day	28% 14% 27% 22% 7% 2	529
	21st to end	Day	24% 15% 31% 22% 8% 1	680
June	1st to 10th	Day	25% 15% 28% 21% 9% 1	630
	11th to 20th	Day	22% 13% 26% 25% 13% 2	630
	21st to end	Day	26% 8% 30% 24% 11% 1	630
July	1st to 10th	Day	18% 8% 33% 27% 13% 2	620
	11th to 20th	Day	16% 7% 30% 31% 14% 2	576
	21st to end	Day	17% 5% 31% 32% 13% 2	488
August	1st to 10th	Day	18% 9% 27% 28% 14% 4	446
	11th to 20th	Day	17% 8% 26% 29% 16% 3	439
	21st to end	Day	19% 13% 20% 26% 16% 5%	495
September	1st to 10th	Day	17% 12% 27% 25% 16% 4	450
	11th to 20th	Day	22% 11% 26% 24% 12% 6%	450
	21st to end	Day	22% 12% 28% 22% 11% 6%	450
October	1st to 10th	Day	18% 12% 30% 21% 14% 4	402
	11th to 20th	Day	28% 15% 26% 18% 10% 3	360
	21st to end	Day	30% 16% 27% 19% 7% 1	396
November	1st to 10th	Day	28% 16% 27% 21% 7% 1	365
	11th to 20th	Day	25% 16% 30% 20% 7% 1	370
	21st to end	Day	27% 16% 30% 22% 5% 1	369
December	1st to 10th	Day	21% 16% 32% 17% 12% 2	180
	11th to 20th	Day	26% 16% 35% 18% 3 1	180
	21st to end	Day	26% 17% 34% 18% 4 1	198
January	1st to 10th	Night	21% 13% 37% 24% 5%	846
	11th to 20th	Night	26% 13% 32% 22% 6%	760
	21st to end	Night	15% 12% 38% 27% 8%	835
February	1st to 10th	Night	18% 13% 41% 22% 5%	720
	11th to 20th	Night	22% 15% 34% 24% 5%	703
	21st to end	Night	22% 11% 34% 28% 4 1	592
March	1st to 10th	Night	19% 10% 38% 29% 4	720
	11th to 20th	Night	22% 13% 33% 24% 8% 1	720
	21st to end	Night	21% 8% 38% 26% 6% 1	792
April	1st to 10th	Night	28% 13% 29% 25% 5%	684
	11th to 20th	Night	24% 12% 31% 26% 7%	534
	21st to end	Night	30% 9% 29% 25% 7%	540
May	1st to 10th	Night	26% 9% 30% 28% 6%	540
	11th to 20th	Night	27% 9% 31% 27% 6% 1	503
	21st to end	Night	22% 10% 33% 29% 6%	389
June	1st to 10th	Night	26% 6% 26% 33% 8% 1	360
	11th to 20th	Night	21% 3 24% 41% 11%	360
	21st to end	Night	23% 6% 27% 32% 13%	360
July	1st to 10th	Night	19% 4 30% 33% 13%	350
	11th to 20th	Night	15% 5% 27% 40% 13%	348
	21st to end	Night	21% 3 21% 38% 16% 1	394
August	1st to 10th	Night	17% 5% 20% 43% 15%	507
	11th to 20th	Night	14% 3 23% 43% 17%	532
	21st to end	Night	11% 5% 28% 38% 16% 2	594
September	1st to 10th	Night	17% 5% 32% 33% 13%	640
	11th to 20th	Night	20% 7% 25% 34% 13% 1	720
	21st to end	Night	21% 8% 27% 31% 13% 1	720
October	1st to 10th	Night	22% 8% 29% 29% 11% 1	720
	11th to 20th	Night	25% 8% 33% 24% 9%	720
	21st to end	Night	28% 11% 33% 22% 6%	792
November	1st to 10th	Night	27% 10% 32% 24% 6% 1	746
	11th to 20th	Night	22% 18% 30% 23% 7% 1	850
	21st to end	Night	24% 14% 32% 25% 5%	850
December	1st to 10th	Night	31% 8% 34% 21% 5% 2	850
	11th to 20th	Night	25% 15% 32% 23% 4	850
	21st to end	Night	27% 16% 30% 22% 4 1	935

Page generated at 2024-01-28 05:26:33. Version ac07

Copyright 2024 Attilla Danko