Overview Realtime Historical Map View
Heat Advisory
2026-07-15T20:00:00-04:00

* WHAT...Heat index values up to 103 expected. * WHERE...Portions of northern Connecticut, central, eastern, northeastern, southeastern, and western Massachusetts, and northern and southern Rhode Island. * WHEN...From 11 AM Tuesday to 8 PM EDT Wednesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS...Temperatures Tuesday night likely remain near 80 for most of southern New England, leading to poor overnight relief.

Charles River At Waltham, Ma Historical Data

Historical Data


Streamflow Range


Date Average 2026 2025 2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011
01-01 549.75
01-02 498.18
01-03 528.64
01-04 533.7
01-05 505.0
01-06 488.82
01-07 453.58
01-08 431.92
01-09 413.25
01-10 464.09
01-11 474.5
01-12 462.17
01-13 483.08
01-14 495.92
01-15 495.08
01-16 473.25
01-17 532.54
01-18 450.0
01-19 502.08
01-20 489.38
01-21 443.25
01-22 439.08
01-23 427.33
01-24 448.62
01-25 471.69
01-26 507.17
01-27 555.18
01-28 527.0
01-29 525.92
01-30 471.31
01-31 444.09
02-01 439.08
02-02 422.85
02-03 432.08
02-04 413.25
02-05 406.46
02-06 374.58
02-07 403.15
02-08 389.36
02-09 388.14
02-10 382.8
02-11 371.55
02-12 377.64
02-13 388.8
02-14 353.32
02-15 383.15
02-16 389.76
02-17 364.26
02-18 391.66
02-19 394.76
02-20 400.98
02-21 396.38
02-22 360.0
02-23 393.23
02-24 392.69
02-25 384.0
02-26 374.67
02-27 408.38
02-28 447.31
02-29 347.33
03-01 421.64
03-02 446.64
03-03 505.64
03-04 508.71
03-05 506.29
03-06 507.86
03-07 532.29
03-08 535.29
03-09 531.57
03-10 482.31
03-11 536.5
03-12 569.38
03-13 542.07
03-14 561.29
03-15 604.36
03-16 611.57
03-17 617.93
03-18 625.07
03-19 582.6
03-20 584.71
03-21 561.73
03-22 570.21
03-23 534.53
03-24 565.0
03-25 566.53
03-26 545.53
03-27 537.0
03-28 545.93
03-29 569.27
03-30 570.67
03-31 608.0
04-01 614.07
04-02 621.67
04-03 568.93
04-04 635.07
04-05 658.8
04-06 632.2
04-07 627.67
04-08 620.6
04-09 607.57
04-10 583.13
04-11 556.13
04-12 515.5
04-13 511.64
04-14 488.93
04-15 474.15
04-16 456.77
04-17 507.85
04-18 490.38
04-19 477.77
04-20 470.38
04-21 465.07
04-22 459.43
04-23 479.86
04-24 494.86
04-25 446.0
04-26 490.07
04-27 504.21
04-28 485.21
04-29 472.79
04-30 464.36
05-01 470.53
05-02 473.71
05-03 455.86
05-04 439.87
05-05 444.79
05-06 440.4
05-07 430.13
05-08 409.71
05-09 389.47
05-10 387.33
05-11 387.0
05-12 364.64
05-13 350.0
05-14 320.46
05-15 305.31
05-16 340.5
05-17 315.0
05-18 310.87
05-19 300.67
05-20 281.79
05-21 297.27
05-22 275.2
05-23 291.8
05-24 294.07
05-25 275.93
05-26 274.25
05-27 260.0
05-28 251.59
05-29 253.2
05-30 257.72
05-31 242.8
06-01 237.4
06-02 229.19
06-03 242.54
06-04 231.89
06-05 209.9
06-06 241.91
06-07 233.96
06-08 283.73
06-09 276.53
06-10 260.19
06-11 262.05
06-12 286.27
06-13 272.26
06-14 273.4
06-15 276.25
06-16 261.08
06-17 264.85
06-18 260.32
06-19 263.97
06-20 234.61
06-21 230.23
06-22 215.69
06-23 211.47
06-24 201.72
06-25 197.24
06-26 190.71
06-27 181.11
06-28 172.87
06-29 191.37
06-30 178.17
07-01 166.28
07-02 184.88
07-03 185.46
07-04 193.42
07-05 190.03
07-06 168.15
07-07 172.01
07-08 172.13
07-09 166.68
07-10 192.97
07-11 216.24
07-12 220.23
07-13 212.56
07-14 217.63
07-15 205.63
07-16 219.87
07-17 220.72
07-18 202.94
07-19 210.41
07-20 188.13
07-21 177.89
07-22 181.84
07-23 175.06
07-24 172.61
07-25 153.32
07-26 162.69
07-27 163.31
07-28 162.46
07-29 173.81
07-30 193.54
07-31 159.08
08-01 159.49
08-02 134.92
08-03 134.7
08-04 122.85
08-05 125.66
08-06 122.59
08-07 115.69
08-08 180.74
08-09 195.49
08-10 198.55
08-11 192.08
08-12 176.38
08-13 162.59
08-14 164.65
08-15 156.39
08-16 161.88
08-17 142.48
08-18 142.52
08-19 136.05
08-20 152.93
08-21 136.58
08-22 131.24
08-23 135.73
08-24 145.39
08-25 137.28
08-26 155.27
08-27 143.18
08-28 153.05
08-29 122.47
08-30 160.84
08-31 141.27
09-01 135.92
09-02 212.16
09-03 214.31
09-04 181.86
09-05 166.27
09-06 160.58
09-07 170.36
09-08 168.81
09-09 178.41
09-10 184.23
09-11 182.11
09-12 171.74
09-13 172.08
09-14 161.14
09-15 151.2
09-16 142.66
09-17 139.91
09-18 135.86
09-19 184.34
09-20 172.97
09-21 164.11
09-22 169.71
09-23 162.33
09-24 161.03
09-25 162.41
09-26 174.23
09-27 167.44
09-28 156.91
09-29 165.61
09-30 189.6
10-01 179.59
10-02 160.72
10-03 157.25
10-04 142.55
10-05 209.65
10-06 165.42
10-07 193.01
10-08 190.62
10-09 183.99
10-10 180.51
10-11 169.31
10-12 164.79
10-13 162.02
10-14 172.64
10-15 173.44
10-16 137.47
10-17 200.51
10-18 183.55
10-19 181.71
10-20 161.62
10-21 178.18
10-22 204.36
10-23 195.63
10-24 225.79
10-25 213.29
10-26 221.24
10-27 227.07
10-28 271.2
10-29 244.07
10-30 299.31
10-31 290.33
11-01 321.5
11-02 330.15
11-03 320.31
11-04 318.86
11-05 299.42
11-06 289.25
11-07 281.03
11-08 260.6
11-09 249.05
11-10 248.55
11-11 245.66
11-12 234.79
11-13 238.2
11-14 240.45
11-15 236.45
11-16 248.79
11-17 267.5
11-18 290.38
11-19 293.77
11-20 292.69
11-21 279.31
11-22 273.85
11-23 274.54
11-24 292.38
11-25 295.23
11-26 294.43
11-27 335.5
11-28 335.0
11-29 306.79
11-30 298.93
12-01 342.21
12-02 340.62
12-03 325.86
12-04 324.79
12-05 315.07
12-06 351.62
12-07 340.71
12-08 350.86
12-09 385.08
12-10 424.57
12-11 443.5
12-12 436.86
12-13 420.43
12-14 456.75
12-15 442.38
12-16 444.24
12-17 458.66
12-18 462.99
12-19 475.98
12-20 491.25
12-21 516.27
12-22 500.5
12-23 484.69
12-24 509.85
12-25 532.67
12-26 549.5
12-27 530.17
12-28 596.55
12-29 581.73
12-30 527.27
12-31 563.25

Annual Peak Streamflow


Seasonal Comparison


Oceanic Nino Index