Goudie Road
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Goudie Road clear sky chart from 2005-11-06 to 2026-07-31.

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	9% 12% 4 9% 5% 5% 5% 4 6% 7% 35%	142900
	Night	8% 13% 5% 10% 5% 5% 5% 4 6% 6% 34%	138812
Transparency	Day	46% 8% 14% 20% 10% 2	142621
	Night	47% 8% 15% 19% 9% 1	138673
Seeing	Day	18% 16% 27% 23% 13% 3	17623
	Night	17% 11% 24% 29% 17% 3	25963

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	8% 18% 9% 18% 9% 6% 5% 4 5% 5% 12%	4723
	11th to 20th	Day	7% 12% 5% 12% 5% 3 3 3 5% 7% 38%	4716
	21st to end	Day	7% 17% 5% 10% 7% 6% 6% 4 5% 5% 29%	5186
February	1st to 10th	Day	13% 19% 6% 12% 6% 4 4 4 5% 4 22%	1696
	11th to 20th	Day	8% 17% 9% 15% 7% 5% 5% 3 4 5% 23%	1845
	21st to end	Day	8% 22% 7% 15% 7% 6% 5% 3 5% 5% 17%	1730
March	1st to 10th	Day	5% 14% 7% 16% 7% 6% 6% 4 7% 6% 22%	4618
	11th to 20th	Day	6% 16% 6% 10% 5% 4 4 3 5% 7% 33%	4811
	21st to end	Day	11% 22% 6% 10% 6% 5% 5% 4 5% 5% 21%	6090
April	1st to 10th	Day	10% 19% 6% 12% 7% 6% 5% 4 5% 6% 20%	2520
	11th to 20th	Day	10% 16% 6% 11% 7% 6% 5% 3 6% 5% 26%	2534
	21st to end	Day	11% 16% 4 10% 6% 5% 5% 3 5% 6% 27%	2851
May	1st to 10th	Day	6% 11% 3 8% 5% 4 4 3 5% 7% 43%	8195
	11th to 20th	Day	10% 14% 4 9% 6% 6% 6% 5% 8% 8% 24%	8160
	21st to end	Day	13% 10% 4 9% 6% 6% 6% 4 6% 8% 27%	9209
June	1st to 10th	Day	19% 11% 4 8% 6% 6% 4 3 4 6% 28%	3150
	11th to 20th	Day	20% 10% 3 9% 6% 5% 5% 4 6% 6% 26%	3331
	21st to end	Day	12% 7% 3 7% 7% 6% 5% 4 6% 6% 35%	3360
July	1st to 10th	Day	5% 3 1 4 3 4 4 3 5% 7% 60%	7129
	11th to 20th	Day	4 3 1 4 3 3 3 3 5% 6% 65%	6460
	21st to end	Day	4 3 2 4 4 4 4 3 7% 9% 56%	7015
August	1st to 10th	Day	4 3 1 4 3 3 5% 5% 7% 8% 57%	4541
	11th to 20th	Day	5% 3 2 5% 5% 5% 5% 4 7% 8% 51%	4470
	21st to end	Day	10% 6% 2 6% 4 4 5% 4 7% 7% 45%	4358
September	1st to 10th	Day	10% 5% 2 5% 3 4 4 3 6% 6% 52%	2400
	11th to 20th	Day	11% 8% 2 6% 5% 5% 5% 3 5% 6% 44%	2360
	21st to end	Day	16% 10% 2 6% 4 4 3 4 5% 7% 39%	2200
October	1st to 10th	Day	11% 10% 3 9% 5% 5% 4 4 4 7% 38%	3287
	11th to 20th	Day	15% 14% 4 9% 4 5% 4 3 5% 5% 31%	3130
	21st to end	Day	14% 13% 5% 10% 6% 4 4 3 4 5% 30%	3200
November	1st to 10th	Day	18% 18% 5% 11% 6% 6% 5% 4 5% 6% 18%	1777
	11th to 20th	Day	13% 20% 6% 11% 6% 5% 5% 4 4 5% 20%	1680
	21st to end	Day	14% 18% 5% 10% 4 5% 5% 5% 7% 5% 22%	1500
December	1st to 10th	Day	7% 13% 5% 10% 6% 5% 5% 4 7% 7% 31%	2360
	11th to 20th	Day	8% 19% 8% 15% 7% 6% 5% 4 5% 5% 19%	2712
	21st to end	Day	7% 17% 7% 14% 7% 6% 7% 4 6% 7% 18%	3596
January	1st to 10th	Night	8% 19% 9% 20% 8% 6% 6% 3 5% 4 13%	8195
	11th to 20th	Night	8% 11% 4 9% 4 4 4 4 7% 7% 38%	8182
	21st to end	Night	7% 15% 5% 11% 6% 5% 5% 4 5% 6% 31%	8994
February	1st to 10th	Night	11% 19% 6% 12% 6% 5% 5% 4 5% 5% 22%	2920
	11th to 20th	Night	8% 18% 7% 12% 5% 5% 4 3 4 5% 28%	2662
	21st to end	Night	7% 21% 7% 12% 7% 5% 4 4 5% 6% 23%	2076
March	1st to 10th	Night	5% 13% 6% 12% 6% 6% 5% 4 6% 8% 29%	5496
	11th to 20th	Night	5% 13% 4 12% 6% 4 4 4 6% 6% 35%	5407
	21st to end	Night	9% 16% 5% 10% 7% 7% 7% 5% 6% 5% 23%	5127
April	1st to 10th	Night	8% 14% 5% 9% 7% 5% 6% 4 7% 7% 30%	2100
	11th to 20th	Night	10% 14% 4 8% 7% 7% 5% 4 5% 6% 31%	2036
	21st to end	Night	9% 13% 4 8% 6% 5% 5% 4 4 7% 36%	1767
May	1st to 10th	Night	5% 7% 3 7% 5% 5% 5% 4 5% 7% 48%	4724
	11th to 20th	Night	7% 13% 4 8% 5% 5% 6% 5% 9% 9% 31%	4700
	21st to end	Night	9% 8% 3 7% 5% 6% 6% 5% 6% 8% 38%	4943
June	1st to 10th	Night	16% 10% 3 7% 4 5% 5% 4 7% 7% 32%	1470
	11th to 20th	Night	16% 8% 3 7% 5% 5% 4 4 7% 6% 35%	1283
	21st to end	Night	8% 6% 3 6% 4 6% 6% 4 6% 8% 43%	1260
July	1st to 10th	Night	4 4 1 4 3 3 3 3 5% 7% 62%	3044
	11th to 20th	Night	3 3 1 4 3 3 3 3 5% 6% 66%	3720
	21st to end	Night	5% 4 1 4 3 3 3 3 5% 7% 62%	4049
August	1st to 10th	Night	4 2 1 4 3 4 5% 5% 6% 8% 59%	2609
	11th to 20th	Night	4 3 1 5% 4 4 5% 3 7% 10% 54%	2577
	21st to end	Night	9% 8% 2 6% 4 4 5% 4 6% 7% 47%	3557
September	1st to 10th	Night	7% 5% 2 5% 4 4 4 3 5% 6% 55%	2000
	11th to 20th	Night	11% 7% 2 5% 4 3 4 3 5% 5% 49%	2040
	21st to end	Night	13% 8% 3 7% 3 4 4 3 5% 8% 41%	2200
October	1st to 10th	Night	9% 10% 3 9% 5% 4 5% 4 5% 5% 41%	3910
	11th to 20th	Night	19% 10% 4 6% 4 3 3 3 6% 7% 35%	4024
	21st to end	Night	12% 15% 5% 11% 5% 4 4 3 4 4 33%	4600
November	1st to 10th	Night	17% 18% 5% 9% 5% 4 4 4 5% 6% 23%	2739
	11th to 20th	Night	15% 18% 6% 11% 6% 5% 4 4 4 5% 23%	2940
	21st to end	Night	12% 20% 6% 11% 6% 5% 4 5% 5% 6% 21%	3098
December	1st to 10th	Night	8% 11% 4 10% 6% 5% 5% 4 6% 7% 35%	5040
	11th to 20th	Night	9% 21% 7% 13% 7% 6% 5% 4 5% 5% 19%	5700
	21st to end	Night	8% 18% 7% 15% 7% 6% 5% 4 5% 5% 21%	7623

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	69% 9% 12% 8% 2	4723
	11th to 20th	Day	46% 6% 19% 20% 6% 3	4740
	21st to end	Day	56% 10% 12% 14% 8%	5187
February	1st to 10th	Day	63% 9% 10% 10% 6% 2	1696
	11th to 20th	Day	63% 8% 11% 12% 6% 1	1854
	21st to end	Day	69% 8% 10% 10% 3	1730
March	1st to 10th	Day	56% 9% 12% 13% 10%	4618
	11th to 20th	Day	47% 7% 15% 24% 7%	4811
	21st to end	Day	61% 8% 12% 11% 9%	6090
April	1st to 10th	Day	62% 10% 12% 12% 4	2520
	11th to 20th	Day	57% 7% 13% 15% 7% 1	2534
	21st to end	Day	55% 8% 13% 17% 7% 1	2851
May	1st to 10th	Day	38% 6% 12% 28% 14% 1	8195
	11th to 20th	Day	50% 9% 16% 21% 4	8163
	21st to end	Day	51% 9% 17% 21% 2	9210
June	1st to 10th	Day	57% 6% 11% 15% 9% 3	3150
	11th to 20th	Day	58% 7% 10% 16% 8% 1	3331
	21st to end	Day	46% 9% 13% 18% 11% 2	3360
July	1st to 10th	Day	23% 5% 12% 24% 22% 13%	7054
	11th to 20th	Day	21% 5% 12% 24% 26% 11%	6385
	21st to end	Day	24% 6% 15% 31% 18% 7%	6822
August	1st to 10th	Day	22% 7% 12% 28% 27% 4	4524
	11th to 20th	Day	28% 8% 19% 33% 11% 2	4512
	21st to end	Day	35% 8% 20% 23% 13% 1	4357
September	1st to 10th	Day	32% 6% 17% 28% 14% 4	2400
	11th to 20th	Day	40% 7% 12% 23% 15% 2	2360
	21st to end	Day	44% 8% 19% 18% 9% 1	2200
October	1st to 10th	Day	45% 6% 20% 24% 6%	3287
	11th to 20th	Day	55% 6% 10% 24% 5%	3130
	21st to end	Day	54% 7% 16% 18% 5%	3200
November	1st to 10th	Day	66% 9% 12% 10% 4	1777
	11th to 20th	Day	66% 9% 12% 10% 3 1	1680
	21st to end	Day	59% 12% 15% 9% 5%	1500
December	1st to 10th	Day	50% 10% 23% 13% 4	2360
	11th to 20th	Day	64% 12% 11% 10% 3	2714
	21st to end	Day	61% 12% 14% 10% 2	3596
January	1st to 10th	Night	71% 10% 9% 8% 2	8195
	11th to 20th	Night	42% 7% 18% 21% 8% 3	8220
	21st to end	Night	53% 9% 12% 16% 10%	8994
February	1st to 10th	Night	62% 7% 12% 11% 6% 1	2920
	11th to 20th	Night	57% 7% 12% 14% 8% 1	2664
	21st to end	Night	60% 7% 13% 12% 7%	2076
March	1st to 10th	Night	47% 9% 15% 18% 11%	5496
	11th to 20th	Night	44% 8% 16% 23% 9%	5408
	21st to end	Night	55% 10% 13% 14% 7%	5127
April	1st to 10th	Night	48% 11% 20% 16% 5%	2100
	11th to 20th	Night	52% 9% 15% 16% 8% 1	2036
	21st to end	Night	46% 8% 13% 21% 10% 1	1767
May	1st to 10th	Night	33% 6% 13% 34% 14%	4721
	11th to 20th	Night	40% 11% 19% 25% 5%	4700
	21st to end	Night	39% 11% 19% 27% 4	4947
June	1st to 10th	Night	48% 9% 13% 17% 12% 2	1470
	11th to 20th	Night	45% 10% 13% 22% 10%	1283
	21st to end	Night	37% 9% 17% 25% 10% 2	1260
July	1st to 10th	Night	21% 4 17% 25% 20% 12%	3010
	11th to 20th	Night	18% 6% 18% 21% 27% 10%	3672
	21st to end	Night	21% 4 15% 34% 18% 7%	3937
August	1st to 10th	Night	21% 5% 11% 32% 27% 4	2601
	11th to 20th	Night	23% 8% 23% 29% 15% 2	2601
	21st to end	Night	34% 6% 18% 26% 13% 2	3557
September	1st to 10th	Night	28% 7% 15% 28% 18% 3	2000
	11th to 20th	Night	35% 7% 13% 23% 19% 3	2040
	21st to end	Night	41% 9% 17% 23% 10% 1	2200
October	1st to 10th	Night	42% 7% 17% 26% 7%	3910
	11th to 20th	Night	48% 6% 11% 23% 12%	4024
	21st to end	Night	53% 7% 16% 19% 5%	4600
November	1st to 10th	Night	61% 9% 12% 12% 5%	2739
	11th to 20th	Night	64% 8% 12% 11% 5% 1	2940
	21st to end	Night	63% 10% 14% 8% 5%	3098
December	1st to 10th	Night	47% 11% 20% 18% 4	5040
	11th to 20th	Night	66% 10% 13% 9% 2	5697
	21st to end	Night	63% 11% 11% 12% 3	7623

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	20% 20% 31% 15% 8% 5%	220
	11th to 20th	Day	15% 21% 28% 23% 11% 3	220
	21st to end	Day	17% 17% 33% 24% 7% 2	242
February	1st to 10th	Day	22% 19% 31% 18% 9% 1	236
	11th to 20th	Day	18% 20% 31% 22% 6% 3	425
	21st to end	Day	21% 17% 33% 18% 10% 1	446
March	1st to 10th	Day	21% 22% 29% 19% 8% 1	540
	11th to 20th	Day	23% 24% 23% 17% 11% 3	540
	21st to end	Day	24% 23% 23% 17% 10% 2	594
April	1st to 10th	Day	19% 23% 29% 21% 8% 1	540
	11th to 20th	Day	21% 21% 26% 19% 9% 4	532
	21st to end	Day	17% 17% 30% 22% 9% 5%	540
May	1st to 10th	Day	14% 21% 27% 24% 10% 3	543
	11th to 20th	Day	20% 14% 23% 23% 17% 4	568
	21st to end	Day	19% 12% 24% 22% 17% 5%	690
June	1st to 10th	Day	21% 13% 27% 24% 13% 2	780
	11th to 20th	Day	24% 16% 24% 22% 12% 2	961
	21st to end	Day	15% 11% 25% 27% 17% 5%	990
July	1st to 10th	Day	12% 13% 25% 30% 17% 4	865
	11th to 20th	Day	8% 13% 33% 30% 13% 3	564
	21st to end	Day	6% 10% 27% 34% 18% 5%	616
August	1st to 10th	Day	7% 10% 25% 31% 20% 8%	527
	11th to 20th	Day	8% 9% 28% 28% 19% 7%	517
	21st to end	Day	13% 12% 26% 29% 14% 6%	583
September	1st to 10th	Day	14% 11% 26% 27% 16% 6%	530
	11th to 20th	Day	16% 10% 28% 27% 15% 4	530
	21st to end	Day	21% 17% 27% 21% 10% 3	530
October	1st to 10th	Day	19% 16% 26% 23% 12% 3	530
	11th to 20th	Day	22% 21% 24% 16% 13% 3	450
	21st to end	Day	26% 15% 30% 20% 7% 2	363
November	1st to 10th	Day	29% 20% 26% 16% 8% 1	289
	11th to 20th	Day	28% 18% 26% 17% 9% 2	220
	21st to end	Day	21% 19% 26% 20% 10% 5%	220
December	1st to 10th	Day	19% 17% 20% 21% 20% 4	220
	11th to 20th	Day	26% 21% 25% 18% 9% 2	220
	21st to end	Day	17% 17% 27% 30% 7% 2	242
January	1st to 10th	Night	24% 18% 25% 23% 9% 1	850
	11th to 20th	Night	16% 14% 30% 27% 12% 1	840
	21st to end	Night	15% 14% 30% 28% 12% 2	924
February	1st to 10th	Night	19% 14% 28% 26% 10% 2	840
	11th to 20th	Night	14% 13% 29% 30% 12% 1	824
	21st to end	Night	16% 16% 23% 24% 18% 3	692
March	1st to 10th	Night	17% 13% 26% 27% 15% 2	840
	11th to 20th	Night	18% 17% 26% 23% 15% 2	840
	21st to end	Night	17% 14% 26% 26% 13% 4	924
April	1st to 10th	Night	14% 11% 24% 32% 15% 4	840
	11th to 20th	Night	15% 11% 25% 31% 16% 2	788
	21st to end	Night	14% 13% 25% 32% 14% 2	507
May	1st to 10th	Night	13% 8% 23% 34% 20% 2	420
	11th to 20th	Night	13% 8% 19% 36% 20% 4	414
	21st to end	Night	16% 7% 19% 27% 26% 5%	455
June	1st to 10th	Night	17% 8% 23% 32% 17% 2	420
	11th to 20th	Night	17% 10% 20% 35% 16% 3	420
	21st to end	Night	10% 6% 20% 38% 24% 3	420
July	1st to 10th	Night	7% 4 17% 33% 35% 3	410
	11th to 20th	Night	5% 6% 22% 34% 30% 3	408
	21st to end	Night	6% 4 14% 38% 34% 4	458
August	1st to 10th	Night	6% 4 12% 35% 34% 10%	398
	11th to 20th	Night	7% 2 14% 34% 37% 6%	396
	21st to end	Night	10% 5% 16% 36% 29% 4	842
September	1st to 10th	Night	10% 6% 16% 34% 28% 7%	800
	11th to 20th	Night	14% 5% 16% 29% 27% 10%	800
	21st to end	Night	19% 8% 21% 30% 18% 5%	800
October	1st to 10th	Night	16% 9% 21% 29% 22% 4	800
	11th to 20th	Night	21% 10% 22% 27% 18% 2	800
	21st to end	Night	22% 12% 25% 27% 11% 3	880
November	1st to 10th	Night	27% 14% 26% 25% 7% 1	820
	11th to 20th	Night	25% 17% 24% 22% 10% 2	840
	21st to end	Night	20% 15% 27% 24% 11% 3	998
December	1st to 10th	Night	16% 14% 26% 29% 12% 2	1050
	11th to 20th	Night	23% 14% 29% 24% 9% 1	1050
	21st to end	Night	21% 16% 31% 24% 7% 1	1155

Page generated at 2026-07-28 00:25:25. Version ac07

Copyright © 2026 Attilla Danko.