Source: Volcano Discovery

Brava (Cape Verde): Seismic activity has decreased since its peak with shallow earthquakes around 2 August which had triggered fears that a new eruption could occur in the near future. Authorities remain at alert while groups of scientists are currently monitoring the situation.

Sinabung (Sumatra, Indonesia): The series of relatively frequent explosions continues. One this morning at 11:03 local time sent an ash plume to 1600 m above the summit.

Reventador (Ecuador): At the moment, this is Ecuador’s most active volcano. According to the Istituto Geofisico (IGEPN), its activity is “high”. A lava dome continues to grow at the summit crater.
Strong degassing generates a plume of steam and gas rising 500-1000 m and frequent small to moderate explosions produce ash plumes that rise to similar heights. In total, IGPEN counted 38 explosions during an 24 hour interval, based on seismic and webcam observations. Most of the time, these can not be observed directly due to frequent cloud cover.
Based on satellite observations, a stronger ash emission was reported by VAAC Washington this afternoon (at 14:18 UTC) with an ash plume reaching 19,000 ft (6.5 km) altitude, or approx. 2 km height above the crater.

Cotopaxi (Ecuador): The activity of the volcano, both internal (seismic, deformation etc) and at the surface, remains low. IGEPN reports that mild steaming and degassing continue.

Nevados de Chillán (Central Chile): Small, sporadic ash emissions continue to occur at the volcano on most days since they re-appeared in late July, showing that the volcano’s superficial hydrothermal system remains disturbed.
According to SERNAGEOMIN volcanologists, this new phase of surface activity is being caused by a small magma intrusion at 4-5 km depth which interacts with (transfers heat and gasses into) the overlying system of circulating fluids (water and gasses) which can become over-pressurized and then generate explosions at the surface (= phreatic activity).

Bristol Island (United Kingdom, South Sandwich Is): The eruption on the remote island seems to have come to and end or paused.
During the past 2 weeks, no more traces of ash emissions or lava flows have been detected on satellite imagery and the heat signal has decreased to more or less zero.

Currently erupting:

Ambrym (Vanuatu): active lava lakes in several craters (updated 12 Jul 2016)
Batu Tara (Sunda Islands, Indonesia): strombolian explosions, ash plumes up to 500 m, extrusion of a small lava dome with rockfalls (updated 28 Nov 2015)
Bristol Island (United Kingdom, South Sandwich Is): new eruption since late April 2016 (updated 21 Jul 2016)
Bromo (East Java, Indonesia): intermittent mild ash emissions (updated 2 Aug 2016)
Chikurachki (Paramushir Island): explosive activity since 27 July 2016 (updated 28 Jul 2016)
Colima (Western Mexico): intermittent mild to moderate explosions (updated 29 Jul 2016)
Copahue (Chile/Argentina): strombolian activity from new intra-crater cone (updated 4 Jul 2016)
Dukono (Halmahera): mild strombolian activity, continuous intense ash emissions (updated 12 Jul 2016)
Erebus (Antarctica): active lava lake in summit crater (updated 8 Dec 2014)
Erta Ale (Danakil depression, Ethiopia): overflowing lava lake (updated 2 Mar 2016)
Fuego (Guatemala): lava flows on S and W flanks, lava fountaining from summit vent (updated 30 Jul 2016)
Gamalama (Halmahera): small ash eruption on 3 Aug 2016 (updated 5 Aug 2016)
Ibu (Halmahera, Indonesia): stromolian and phreatomagmatic explosions (updated 29 Oct 2015)
Kilauea (Hawai’i): new surface lava flows from breakouts N and NE of Puu Oo since 24 May 2016 (updated 28 Apr 2015)
Klyuchevskoy (Kamchatka): strombolian explosions in summit crater, active lava flows on SE flank (updated 25 Jul 2016)
Masaya (Nicaragua): active lava lake ini summit crater (updated 12 Jul 2016)
Nevado del Ruiz (Colombia): intermittent mild to moderate ash emissions (updated 29 Jul 2016)
Nevados de Chillán (Central Chile): sporadic ash emissions (updated 2 Aug 2016)
Nyiragongo (DRCongo): new vent on crater floor (updated 1 Jun 2016)
Ol Doinyo Lengai (Tanzania): effusion of natrocarbonatite lava inside the crater (updated 8 Jul 2013)
Pacaya (Guatemala): strombolian explosions (updated 29 Jul 2016)
Popocatépetl (Central Mexico): degassing, sporadic explosions, slowly growing lava dome (updated 1 Aug 2016)
Reventador (Ecuador): lava flow on SW flank (updated 24 Feb 2016)
Sakurajima (Kyushu, Japan): sporadic vulcanian explosions from Minamidake and Showa crater (updated 25 Jul 2016)
Sangay (Ecuador): mild strombolian activity in summit crater (updated 20 May 2016)
Santiaguito (Guatemala): intermittent strong explosions from growing Caliente dome (updated 5 Aug 2016)
Semeru (East Java, Indonesia): growing lava dome, mild strombolian activity in summit crater (updated 29 Jul 2016)
Shiveluch (Kamchatka): growing lava dome (updated 29 Jul 2016)
Sinabung (Sumatra, Indonesia): continuing pyroclastic flows (updated 5 Aug 2016)
Stromboli (Eolian Islands, Italy): weak, intermittent strombolian explosions (updated 23 May 2016)
Turrialba (Costa Rica): near-continuous ash emissions (updated 25 Jul 2016)
Villarrica (Central Chile): lava lake in summit crater, spattering, strombolian explosions (updated 4 Apr 2016)
Yasur (Tanna Island, Vanuatu): ash emissions, weak strombolian explosions (updated 13 Nov 2015)

More continued coverage and updates at Volcano Discovery: Volcanic Activity Worldwide