Gold River
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Gold River clear sky chart from 2005-11-05 to 2017-09-21.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
27%
14530
8%
46823
6%
14500
30%
14500
11%
37500

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
19%
750
10%
2686
8%
746
23%
746
7%
2283
January16th to endNight
21%
800
8%
2790
7%
800
23%
800
7%
2326
February1st to 15thNight
15%
703
5%
2302
4%
702
17%
702
6%
2017
February16th to endNight
25%
632
11%
2047
8%
632
29%
632
11%
1621
March1st to 15thNight
14%
720
3%
2046
1%
720
15%
720
5%
1830
March16th to endNight
15%
768
5%
2112
3%
768
17%
768
6%
1886
April1st to 15thNight
22%
614
6%
1724
3%
614
23%
614
8%
1502
April16th to endNight
20%
540
7%
1620
5%
540
22%
540
9%
1362
May1st to 15thNight
33%
399
10%
1479
12%
399
37%
399
11%
1120
May16th to endNight
35%
375
4%
1322
3%
374
37%
374
11%
1042
June1st to 15thNight
38%
360
2%
1260
1%
360
39%
360
13%
962
June16th to endNight
31%
360
2%
1260
1%
360
32%
360
11%
982
July1st to 15thNight
56%
340
5%
1190
3%
340
58%
340
24%
729
July16th to endNight
63%
376
11%
1239
13%
354
66%
354
30%
709
August1st to 15thNight
70%
520
13%
1567
13%
518
71%
518
32%
944
August16th to endNight
52%
573
14%
1719
12%
573
54%
573
23%
1179
September1st to 15thNight
58%
681
21%
1800
12%
681
61%
681
35%
1128
September16th to endNight
34%
680
12%
1881
9%
680
36%
680
16%
1446
October1st to 15thNight
28%
660
8%
1972
5%
660
32%
660
15%
1513
October16th to endNight
20%
704
5%
2224
3%
704
23%
704
8%
1903
November1st to 15thNight
7%
700
4%
2450
1%
700
11%
700
3%
2217
November16th to endNight
14%
725
6%
2553
3%
725
19%
725
7%
2138
December1st to 15thNight
17%
750
7%
2700
3%
750
21%
750
7%
2191
December16th to endNight
11%
800
6%
2880
3%
800
16%
800
6%
2470

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 ForecastData
Points
Cloud CoverDay
29%14%36%42333423%
48083
Night
30%15%36%42333422%
46967
Cloud CoverDay
28%15%46%42333423%
48083
Night
28%15%36%42333422%
46970
TransparencyDay
65%5%9%12%6%1
47731
Night
66%49%11%6%1
46823
SeeingDay
37%13%21%19%6%1
6532
Night
39%6%21%20%11%1
14533

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
40%19%3431122316%
1253
16th to endDay
36%16%46%5%2223314%
1434
February1st to 15thDay
36%21%5%431332412%
1561
16th to endDay
22%23%36%42433421%
1427
March1st to 15thDay
38%26%46%4121128%
1914
16th to endDay
34%27%47%42221210%
2112
April1st to 15thDay
29%23%5%7%5%2423311%
2223
16th to endDay
35%20%47%42222313%
2340
May1st to 15thDay
25%14%46%6%34335%21%
2472
16th to endDay
30%13%5%9%5%24335%15%
2788
June1st to 15thDay
30%11%46%43335%5%20%
2700
16th to endDay
34%12%5%6%5%3433417%
2700
July1st to 15thDay
19%8%25%323446%39%
2700
16th to endDay
17%6%35%423346%41%
2846
August1st to 15thDay
12%5%24415%35%8%45%
2382
16th to endDay
20%6%25%5%445%5%6%34%
2483
September1st to 15thDay
15%7%245%23435%45%
2157
16th to endDay
30%8%35%5%34335%26%
1872
October1st to 15thDay
30%11%36%42442325%
1658
16th to endDay
41%12%3442333315%
1645
November1st to 15thDay
50%15%45%4132219%
1408
16th to endDay
36%17%35%32312317%
1404
December1st to 15thDay
34%14%45%32221324%
1260
16th to endDay
35%25%45%31221214%
1344
January1st to 15thNight
41%16%3442222217%
2686
16th to endNight
35%17%35%42333415%
2790
February1st to 15thNight
34%18%5%6%5%2332313%
2290
16th to endNight
24%20%46%42323324%
2047
March1st to 15thNight
31%25%5%8%5%1323211%
2046
16th to endNight
32%25%45%41234311%
2108
April1st to 15thNight
25%24%46%5%3433315%
1724
16th to endNight
29%18%47%5%3433318%
1620
May1st to 15thNight
23%13%37%5%2433426%
1478
16th to endNight
21%13%47%6%25%445%23%
1322
June1st to 15thNight
22%10%46%434446%27%
1260
16th to endNight
26%10%36%6%3345%5%24%
1260
July1st to 15thNight
15%6%35%314346%45%
1260
16th to endNight
13%42342325%6%50%
1323
August1st to 15thNight
8%6%23315%448%50%
1574
16th to endNight
16%7%26%43345%7%36%
1719
September1st to 15thNight
11%6%24314345%51%
1800
16th to endNight
29%9%36%5%13335%28%
1881
October1st to 15thNight
31%10%36%42333427%
1972
16th to endNight
40%12%36%5%23335%14%
2224
November1st to 15thNight
50%14%46%3132229%
2450
16th to endNight
34%18%46%41212319%
2553
December1st to 15thNight
34%15%35%5%2323419%
2700
16th to endNight
38%20%35%41212315%
2880

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
37%19%45%21232316%
1253
16th to endDay
33%19%46%5%2234315%
1434
February1st to 15thDay
33%21%5%7%32333312%
1561
16th to endDay
21%24%45%423335%21%
1427
March1st to 15thDay
34%29%5%6%3221229%
1914
16th to endDay
32%27%6%6%5%2212210%
2112
April1st to 15thDay
26%27%5%7%5%2323212%
2223
16th to endDay
33%22%5%6%42222213%
2340
May1st to 15thDay
25%16%37%5%3433421%
2472
16th to endDay
32%12%5%9%5%2434415%
2788
June1st to 15thDay
31%11%46%5%24345%19%
2700
16th to endDay
35%11%47%5%2423417%
2700
July1st to 15thDay
19%6%35%423445%39%
2700
16th to endDay
18%7%25%423446%41%
2846
August1st to 15thDay
12%6%344245%47%45%
2382
16th to endDay
20%7%24435%5%46%34%
2483
September1st to 15thDay
15%7%245%1343445%
2157
16th to endDay
30%8%36%5%24335%26%
1872
October1st to 15thDay
31%9%48%42432324%
1658
16th to endDay
42%11%35%5%2243415%
1645
November1st to 15thDay
49%17%443132219%
1408
16th to endDay
35%18%46%42311318%
1404
December1st to 15thDay
31%17%36%42122323%
1260
16th to endDay
32%27%45%32321114%
1344
January1st to 15thNight
39%17%3442222317%
2685
16th to endNight
34%17%35%42334415%
2790
February1st to 15thNight
32%19%5%6%6%2323313%
2290
16th to endNight
22%21%46%32324423%
2047
March1st to 15thNight
28%26%5%8%5%2232311%
2046
16th to endNight
28%26%5%5%5%2433311%
2112
April1st to 15thNight
24%24%47%5%3433315%
1724
16th to endNight
27%19%47%5%3333317%
1620
May1st to 15thNight
23%14%36%5%2433426%
1478
16th to endNight
22%12%48%7%25%44423%
1322
June1st to 15thNight
23%11%47%423437%27%
1260
16th to endNight
25%10%47%6%33445%23%
1260
July1st to 15thNight
14%8%14224346%45%
1260
16th to endNight
13%423413347%50%
1323
August1st to 15thNight
9%6%2342345%6%51%
1574
16th to endNight
16%7%26%5%3445%7%37%
1719
September1st to 15thNight
11%6%23423445%51%
1800
16th to endNight
29%9%36%423335%28%
1881
October1st to 15thNight
31%8%36%42333427%
1972
16th to endNight
39%13%35%42333315%
2224
November1st to 15thNight
49%16%35%3222129%
2450
16th to endNight
33%20%46%5%1322318%
2553
December1st to 15thNight
32%16%45%5%2323418%
2700
16th to endNight
36%21%45%42222315%
2880

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
75%336%7%3
1253
16th to endDay
75%35%7%43
1434
February1st to 15thDay
77%446%5%1
1561
16th to endDay
67%38%11%7%
1427
March1st to 15thDay
84%25%6%1
1914
16th to endDay
83%25%7%1
2112
April1st to 15thDay
79%36%7%3
2223
16th to endDay
77%45%8%4
2340
May1st to 15thDay
66%410%12%5%
2472
16th to endDay
71%6%9%10%2
2792
June1st to 15thDay
66%7%11%10%4
2700
16th to endDay
71%6%9%9%2
2700
July1st to 15thDay
44%6%18%19%9%1
2541
16th to endDay
41%6%17%24%9%
2667
August1st to 15thDay
37%7%18%24%9%2
2364
16th to endDay
47%7%19%18%6%
2483
September1st to 15thDay
41%5%12%23%15%1
2157
16th to endDay
60%5%10%11%9%1
1872
October1st to 15thDay
64%5%7%11%9%
1658
16th to endDay
73%47%9%4
1645
November1st to 15thDay
83%35%321
1408
16th to endDay
75%246%7%2
1404
December1st to 15thDay
67%48%10%6%3
1260
16th to endDay
79%335%5%2
1344
January1st to 15thNight
75%237%7%3
2686
16th to endNight
72%35%7%5%4
2790
February1st to 15thNight
78%337%42
2302
16th to endNight
66%47%13%8%
2047
March1st to 15thNight
80%37%5%2
2046
16th to endNight
78%46%8%1
2112
April1st to 15thNight
73%6%6%10%3
1724
16th to endNight
72%36%11%6%
1620
May1st to 15thNight
62%410%15%7%
1479
16th to endNight
62%7%15%11%2
1322
June1st to 15thNight
58%7%15%11%6%
1260
16th to endNight
60%8%14%13%3
1260
July1st to 15thNight
39%5%21%17%13%1
1190
16th to endNight
30%9%24%24%10%1
1239
August1st to 15thNight
32%7%21%25%10%1
1567
16th to endNight
45%7%18%20%7%
1719
September1st to 15thNight
34%5%14%23%20%1
1800
16th to endNight
58%5%11%11%9%2
1881
October1st to 15thNight
61%310%13%10%
1972
16th to endNight
73%47%8%4
2224
November1st to 15thNight
83%345%11
2450
16th to endNight
74%247%7%3
2553
December1st to 15thNight
70%37%10%5%2
2700
16th to endNight
77%25%5%5%3
2880

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
18%333%25%15%5%
60
16th to endDay
53%7%21%12%5%
154
February1st to 15thDay
52%10%23%12%
236
16th to endDay
39%15%24%15%4
211
March1st to 15thDay
58%21%14%4
260
16th to endDay
56%13%18%7%21
288
April1st to 15thDay
47%17%21%9%3
269
16th to endDay
54%17%17%8%1
270
May1st to 15thDay
39%21%19%15%21
288
16th to endDay
32%15%25%16%7%2
503
June1st to 15thDay
39%16%20%17%4
495
16th to endDay
37%16%19%20%41
495
July1st to 15thDay
26%13%23%29%6%1
475
16th to endDay
19%9%24%35%9%1
515
August1st to 15thDay
14%5%23%36%15%4
342
16th to endDay
24%10%25%26%10%3
332
September1st to 15thDay
24%10%26%23%11%2
315
16th to endDay
36%14%19%19%9%1
276
October1st to 15thDay
39%10%27%16%5%
255
16th to endDay
51%11%21%9%5%
249
November1st to 15thDay
55%16%15%11%1
60
16th to endDay
48%8%13%8%8%13%
60
December1st to 15thDay
45%16%15%16%33
60
16th to endDay
51%414%21%6%1
64
January1st to 15thNight
50%6%20%17%4
750
16th to endNight
46%6%21%16%7%1
800
February1st to 15thNight
46%6%24%19%3
706
16th to endNight
37%8%24%21%7%
632
March1st to 15thNight
47%11%21%15%4
720
16th to endNight
48%10%18%14%6%1
768
April1st to 15thNight
39%8%22%20%6%1
614
16th to endNight
39%6%27%20%5%
540
May1st to 15thNight
33%420%20%19%1
399
16th to endNight
27%320%32%15%1
375
June1st to 15thNight
29%5%18%25%20%1
360
16th to endNight
30%423%26%13%
360
July1st to 15thNight
18%315%32%27%1
340
16th to endNight
14%213%32%34%2
376
August1st to 15thNight
13%19%34%36%4
520
16th to endNight
21%216%33%22%2
573
September1st to 15thNight
15%318%29%28%5%
681
16th to endNight
34%420%24%14%2
680
October1st to 15thNight
38%323%21%11%1
660
16th to endNight
48%5%22%15%6%2
704
November1st to 15thNight
60%6%22%9%1
700
16th to endNight
45%9%24%12%5%1
725
December1st to 15thNight
43%7%24%18%4
750
16th to endNight
52%9%22%13%2
800
Page generated at 2017-09-22 04:35:29. Version ac04

Copyright 2017 A. Danko


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